Apple’s main concern about multitasking has always been its negative effect on battery life. But this morning, noting that “we weren’t the first to this party, but we’re going to be the best,” Steve Jobs announced that iPhone OS 4 will, indeed, offer multitasking.

No real specifics yet on how the company overcame the power issue, but SVP of Software Scott Forstall took the stage to talk about seven multitasking services that will be available to developers:

• Background audio streaming
• Voice over Internet protocol (VoIP)
• Background location
• Push notifications
• Local notifications
• Task completion
• Fast app switching

Jobs noted that multitasking will be available only for the iPhone 3GS, third-generation iPod touch and iPad.

Apple’s (AAPL) plan to preview iPhone OS 3.0 tomorrow is a sure sign that the company is on track to debut the next iteration of the phone on which it will run this summer. That’s the word from Piper Jaffray analyst Gene Munster, who has high expectations for the OS and device both. “In the past two weeks Apple has introduced new Mac hardware and a new iPod shuffle, for which the company simply issued a press release,” Munster wrote in a research note. “The fact that Apple is hosting an event for the iPhone OS 3.0 shows that it will likely involve meaningful changes to the iPhone feature set. Apple may be settling into an annual summer hardware refresh cycle with the iPhone, similar to the iPod’s fall refresh cycle.”

Just what does Munster mean by “meaningful changes”? Like others, he anticipates the addition of universal search, background processing/multitasking and the long pined-for cut and paste.

Incidentally, Munster says he doesn’t expect Apple CEO Steve Jobs, who is on medical leave from the company until June, to attend tomorrow’s event. Tim Cook will be filling the Jobs role for the time being, he says–as much as possible, anyway. Said Munster, “During Jobs’ absence, the pace of innovation at Apple has continued, which we believe will reassure investors. Increasingly, we believe investors are considering the future of Apple under Cook’s leadership as a positive.”