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.

I wrote:

Many would not be surprised if one of these current directors is named to lead Yahoo, even temporarily, and to get a new CEO in place by the New Year (a board priority): John Chapple, Maggie Wilderotter or Frank Biondi Jr.

But a dark horse outside CEO–with the public company experience the board of Yahoo is looking for as its top priority–could emerge.”

The Wall Street Journal raised such a name in a piece today–former Vodafone Group (VOD) CEO Arun Sarin (pictured here).

It’s an intriguing idea, to be sure, and the mobile phone experience is important going forward. (Also interesting is the one-time idea floated of merging Yahoo and Vodafone.)

More to the point, Sarin meets the list of key criteria the board has created, as noted in a previous post I did here:

The board, though, has apparently made a list of six–I have no idea why that is the number chosen–clear criteria for the new leader of Yahoo.

The first is that the candidate have ‘extensive’ experience as the CEO of a public company. Another calls for media and advertising expertise. And mergers and acquisitions experience. Also strategic skills.”

The 54-year-old Sarin fits all that, according to the Journal story; plus he also served on the Cisco (CSCO) board with Yang. He is also quite friendly with the Yahoo (YHOO) co-founder (another important thing, since Yang is sticking around as Chief Yahoo).

While his Vodaphone tenure was not without controversy–apparently, some thought he was too slow to diversify, a major uh-oh for the glacial Yahoo, and a less-than-firm central leader–Sarin did do a lot of turnaround work and has been involved in big acquisitions and cost-cutting.

Sarin also has lots of Silicon Valley experience–he ran InfoSpace (INSP) during the Web 1.0 bubble and was also involved in the troubled joint-investment venture between Accel Partners and Kohlberg Kravis Roberts.

Two more clear uh-ohs to me. But nobody’s perfect, I guess, and stumbles are not necessarily negatives in Silicon Valley–they’re called experience!

In that dark horse vein, sources mention several names like Sarin, who also fit the Yahoo board’s list. One I have mentioned before–Hewlett-Packard (HPQ) exec Todd Bradley–has a similar background at palmOne as CEO, for example.

And here’s another idea (all mine!) for the still-mulling Yahoo board: former Adobe CEO Bruce Chizen (pictured here), who left the media software company after many years, in November, quite abruptly, despite a very good reputation as a leader.

I have no idea why Chizen left Adobe (ADBE). But he is only 52 years old and has lots of acquisition, strategy and cost-cutting and tech experience.

Whatever names are funneling into the final pool, the Journal story noted the selection could be weeks away, although sources I have spoken to close to the situation said Yahoo was trying to move much faster and by year’s end.

That’s a better plan, since Yahoo needs clarity, and soon, in order to decide quickly what to do about both its potential search deal with Microsoft (MSFT) and its merger talks with Time Warner (TWX) online unit AOL.

While the board of directors should spend as much time as it needs to pick the right person, the fact that it has wasted so much time on not doing something about long-term and obvious leadership problems at Yahoo is the clearest sign of its true failure.