Piper Jaffray analyst Gene Munster said this morning that his initial estimates of 900,000 iPads sold in the June quarter and 2.7 million in calendar year 2010 “may prove to be conservative.”

Munster figures Apple (AAPL) is poised to sell between 200,000 and 300,000 iPads this weekend–in line with the 270,000 first-gen iPhones it sold at launch. And he thinks the chances are good that the company will sell out of the device.

“When Apple began taking pre-orders customers could pre-order for home delivery on April 3 or in-store pickup on April 3,” Munster writes. “A week before the launch (on March 27) the company pushed back the shipping date to April 12 and ended the in-store reservation program for the launch. And in preparation for the launch, on March 31 Apple retail stores began calling those with iPad pickup reservations to confirm the reservation.”

What does it all mean? Says Munster: “We believe these signs indicate that initial demand for iPads was stronger than the company expected, and/or minor supply issues have slightly constrained availability for the launch. We believe the supply constraints are minor because the new ship date is not a significant delay. Ultimately, both strong demand and somewhat constrained supply appear to be resulting in the fact that Apple is selling every iPad it can build.”

Munster’s bullish estimate follows two others issued earlier this week–one from Bernstein analyst Toni Sacconaghi, who expects iPad sales to hit five million units in the first year, and another from Morgan Stanley (MS) analyst Katy Huberty, who expects the company to sell over six million units.

[Image credit: Panelfly]

On Tuesday, the company released an AT&T (T)-compatible version of the device. Now comes news that Google is prepping one for Sprint as well. No word yet on availability or pricing, though Sprint (S) says it plans to keep the latter “simple.” Odd that the company would announce the device without divulging a price.

Today’s announcement means the Nexus One will soon be available on all four major U.S. carriers and that we’ll finally get to see whether Google’s (GOOG) plan to upend the consumer-carrier relationship by selling the device directly to consumers over the Web is going to work.

Last week, Canaccord Adams analyst Peter Misek warned that a bottleneck at Apple’s manufacturing partner might limit initial availability of the device or delay its launch. Then yesterday, Digitimes–not the most reliable of sources–published a report suggesting there would be no such inventory issues or delays.

Now, ThinkEquity analyst Vijay Rakesh has issued a note echoing Misek’s claim.

“Our checks in Taiwan indicate some minor delays on the iPad,” Rakesh writes. “The manufacturing of the iPads was supposed to pick up in February, but volumes even in March are still low. Current volumes are much lower than the market expected but most checks are indicating minor delays.”

Rakesh says his checks suggest that iPad production volumes are currently at about 200K to 250K for the month, but should ramp up to 800K to one million per month by April or May. “We believe this is just a minor hiccup in a longer-term entirely new revenue stream and product roadmap for [Apple],” he says.

Who best to believe, if we are to believe anyone at all? Honestly, I have no idea. As I mentioned, Digitimes doesn’t exactly have a great track record when it comes to Apple (AAPL) rumors. Neither does Misek, really. That said, the fact that channel checks conducted by two research houses both found production issues in Apple’s iPad manufacturing, suggests there may be something here.

In a research note this morning, Canaccord Adams analyst Peter Misek says he has heard rumblings that production issues at Apple’s (AAPL) manufacturing partners may keep the company’s iPad in short supply when it first goes on sale.

“We have…heard that the upcoming iPad launch may be somewhat limited as a manufacturing bottleneck has impacted production of Apple’s newest device,” Misek writes.

“An unspecified production problem at the iPad’s manufacturer, Hon Hai Precision,” the analyst explains, “will likely limit the launch region to the US and the number of units available to roughly 300K in the month of March, far lower than the company’s initial estimate of 1,000K units.”

Looking ahead, he adds, “The delay in production ramp will likely impact Apple’s April unit estimate of 800K as well. It is also possible that, given the limited number of units available in March, the launch will be delayed for a month.”

If Misek is right–and that’s a big if; Misek’s prediction earlier this year that Apple would debut a brand new iPhone on Verizon (VZ) at its January special event proved woefully off–it’s a slight setback for Apple, which obviously wants to take good advantage of enthusiasm for the device to really blow out first-year sales. That said, since this would be only a temporary production delay, it probably wouldn’t have that much effect on sales.

Says Misek: “We believe that the only material impact from the iPad delay could come in the form of frustrated consumers and some modest loss of lustre for the company’s product launch.” He figures Apple will sell 550,000 units in its third quarter, which ends in June, 1.2 million in fiscal year 2010 and 3.5 million in 2011.

iPhone OS 4.0. And the iPhone 4G–on Verizon (VZ).

That’s the word from Canaccord Adams analyst Peter Misek, who believes there’s “a good chance” we’ll hear about all three come next Wednesday.

“Together with our semi-conductor partners, we have ascertained that there is a reasonable chance the Asian supply chain is prepping for mass production of a new iPhone in March, for availability in late Q2, likely June,” Misek wrote in a note to clients today.

“The phone will be carried on Verizon and hence will operate on the CDMA network,” he asserts, adding, “however, it will also support European GSM and HSPA standards. An updated 4GS version that will support LTE is anticipated to arrive in June 2011.”

As to the cost, the analyst expects change. “At this moment, we have not heard about the pricing of the device, but believe it will be different from what it is at the moment. While we remain of the view that tiered data plans are imminent, our checks indicate the new iPhone from Verizon will still come with an unlimited data plan.”

Now, I have no idea how much credence to give speculation like this, nor do I have any insider insight into Apple’s carrier negotiations. But I will say this: It seems unlikely that Apple will announce a new iPhone and carrier partnership right after unveiling a brand new, and presumably revolutionary, product.

It might do so before, though. After all, the debut of the iPhone at Macworld 2007 was prefaced by the announcement of Apple TV.

[Image credit: Robert Davis / iLounge]

Remarking on Apple’s (AAPL) December quarter in a note to investors this morning, Thomas Weisel Partners analyst Doug Reid said iPhone and iMac sales for the period have been quite strong. “Our checks suggest December quarter sales of iPhones are tracking ahead of our prior estimates, driven by increased market penetration in the United States, additional carrier agreements in multiple countries, and first-time launches in Korea and China,” Reid wrote.

“Mid-December Apple Store and carrier checks indicate that the 2009 holiday shopping season has seen a sharp increase in the purchase of iPhone as a gift option,” the analyst continued. “We also estimate better than expected iMac sales in the quarter following a successful product refresh (announced on October 20). Our checks indicate strong demand throughout the holiday season for the new iMac line.”

Seems that the shipping delays associated with Apple’s new 27-inch iMacs haven’t undermined sales nearly as much as some feared. Reid says that demand and in-store availability of both 21.5-inch and 27-inch models remains strong, so much so that he’s raising his iMac unit estimate for the December quarter from 655 thousand to 721 thousand.

Demand for the iPhone has also been strong thanks to the end of carrier-exclusivity agreements in some markets.

“The ability to add iPhones to existing family service plans with carriers has been a key driver in C4Q09, our checks indicate. In addition, industry checks also suggest that AAPL is benefiting from the addition of second or third carriers in markets (e.g. UK, Canada) and from a strong initial sales ramp in Korea.”

How much of a benefit? A sizable one. Reid figures Apple will sell 8.21 million to 8.89 million iPhones during the December quarter. And he expects the company to sell 31.59 million to 32.27 million in fiscal 2010.

Five dollars and a ratty “Think Different” T-shirt says Apple shares will hit another new 52-week high today.