First, the departure has jarred the confidence of investors who have pushed the value AMD stock up by more than 57 percent since September. Shares are down by more than 8 percent today.

Second there’s the problem of hiring a replacement for Meyer, who had been on the job only a little more than two years. I’ve been talking to people both inside AMD and longtime AMD watchers outside of the company and practically all of them have been having trouble coming up with a short list of potential candidates.

For one thing, I’m hearing from people familiar with the thinking of those involved in the hiring process that there’s a strong preference for an external candidate.

Among the criteria are someone with a proven record of running large technology companies, and one with some charisma who can get the marketplace excited about AMD again. While Meyer deserves credit for getting AMD back on relatively stable footing following the divestiture of its manufacturing operations–now GlobalFoundries — and his predecessor, Hector Ruiz, gets the credit for doing the heavy lifting of getting the complicated transaction related to that split, neither could be described as charismatic.

Historically, AMD knows what it’s like to have a charismatic CEO. Jerry Sanders who founded the company and ran it from 1969 until 2002, possessed plenty of it, and some of the more colorful anecdotes about Silicon Valley history concern him. The board wants someone who’s both capable and cool at the same time. Someone who can represent the company well to the outside world, bring an air of stability and competence and elaborate a vision that will move the company forward. That’s a tall order for a company like AMD, whose fundamental strategic problem can be summed up in a single phrase: Competing with Intel is brutal, no matter what you do.

The list of potential candidates isn’t obvious by any stretch. Still in my conversations today, a few names came up, some more idealistic than realistic. One internal candidate who will probably get courtesy consideration I’m told is Rick Bergman, senior vice president and general manager for AMD’s products group. He oversees both the graphics and microprocessor operations and came to AMD in 2006 as a senior executive at ATI, the graphics chip company that AMD acquired for $5.4 billion in 2006. His résumé includes time at Texas Instruments and IBM. He’s described by those who know him as hard-driven and competitive and a capable well-respected manager, though at the end of the day not likely to get the nod.

Another name that has come up is that of Pat Gelsinger, not necessarily because he’d be a candidate for the job, but more as an example of the kind of person AMD would like to hire. Gelsinger was Intel’s CTO from 2001 to 2005 and was senior corporate vice president for the Digital Enterprise Group until 2009, when he suddenly jumped to EMC as president, COO and apparent successor-in-waiting to CEO Joe Tucci.

Finally there’s Michael Capellas, whose name invariably comes up whenever a significant CEO slot comes open. He’s currently running Acadia, a private cloud computing joint venture between Cisco Systems and EMC with investments from Intel and VMWare. Capellas was the CEO of Compaq Computer when Hewlett-Packard acquired it in 2002, then went on to helm MCI and engineered its turnaround and sale to Verizon in 2006. His next stop was the payment giant First Data after it was taken private in a leveraged buyout by the private equity fund Kohlberg Kravis Roberts. He was considered for the CEO job at Hewlett-Packard, before Léo Apotheker was named, but was said not to be interested. He’s got the tech and management chops and has a proven record for getting troubled companies on solid footing. It’s unclear if he would be interested.

Whoever they pick, they may want to do it quickly. AMD has a tough road ahead of it, and uncertainty at the top certainly isn’t going to help.

For EMC, the acquisition of Isilon gives it a stake in the network-attached storage space, a fast-growing market for “big data” storage (think movie studio catalogs and gene sequencing information) currently dominated by the likes of NetApp and the site of some other big acquisitions this year–Hewlett-Packard’s purchase of 3Par for $2.4 billion, for example. “The unmistakable waves of cloud computing and ‘big data’ are upon us,” EMC CEO Joe Tucci said in a statement. “Customers are looking for new ways to store, protect, secure and add intelligence to the vast amounts of information they will accumulate over the next decade.”

The move, which will be effective immediately upon its announcement, is quite a blow for Intel (INTC). Gelsinger had done stints as the company’s chief technology officer and as head of its research division. He helped quarterback Intel’s 386 and 486 processors, played a major role in the launch of Nehalem and had been considered a likely successor to Intel CEO Paul Otellini. Now he’s a contender for the top job at EMC (EMC) when CEO Joe Tucci decides to step down.