In a shift that is sure to be much commented on by the advertising industry, Yahoo has tapped Goodby, Silverstein & Partners to take the lead for creative, advertising, digital marketing and strategic planning efforts.

The San Francisco-based Goodby, which is owned by the Omnicom Group (OMC), is known for its innovative ideas and has done such memorable campaigns as the Slowsky turtles for Comcast (CMCSA), the weird folk of Emerald Nuts, owned by Diamond Foods (DMND)–as well as campaigns for tech companies such as Hewlett-Packard (HPQ), Adobe Systems (ADBE) and Netflix (NFLX).

Also, of course, the terrifically memorable “Got Milk?” campaign.

Perhaps a “Got Yahoo?” campaign is in the future?

Until now, the top job of goosing Yahoo’s tarnished brand, as part of a recently launched $100 million marketing push, has been helmed by Ogilvy & Mather, a unit of the WPP Group (WPPGY).

While Goodby will lead on creative initiatives worldwide, Ogilvy will remain in the mix, Integrated Marketing and Brand Management SVP Penny Baldwin told BoomTown in an interview this afternoon, focusing on international marketing efforts, including all upcoming brand launches in France, Taiwan, Hong Kong, Korea, Brazil and Indonesia.

And, via it Neo and Mindshare units, Yahoo said, Ogilvy will also run all media buying for the Internet giant globally.

Yahoo (YHOO) is also keeping strategic branding firm Landor & Associates.

Goodby, Ogilvy and Landor will apparently form a Brand Advisory Board at Yahoo, run by Baldwin.

Baldwin stressed that the move was a broadening of its outside marketing advisers and was not a replacement of Ogilvy, or any indication that the current new marketing campaign needed to change.

She said internal reports on the effectiveness of the overall big theme, “It’s Y!ou,” launched last month, have been strong.

Nonetheless, Baldwin added that the new agency is sure to bring more ideas to the mix in the massive effort, which has included television, print, outdoor and online ads.

And, she noted, the location of Goodby’s HQ in San Francisco, not far from Yahoo’s Sunnyvale digs, was also a plus.

“Goodby has the caliber to serve worldwide needs,” said Baldwin. “And with the way the Web moves so fast, we thought it was also important to have deep resources locally.”

Up next, she added: to “root our brand strategy with more hard-hitting” messages about Yahoo.

“This is far more than just an advertising effort,” said Baldwin of Yahoo’s efforts to revitalize itself in the eyes of consumers–and, while she did not say so, to the digerati of Silicon Valley. “This is a business transformation.”

Here is Baldwin’s boss, Yahoo CMO Elisa Steele talking about the company’s marketing efforts of late in a video interview with Nicki Dugan on the company’s Yodel Anecdotal blog in a new feature called Yodelcast (sorry, Nicki, but it is simply too professional and unjiggly for BoomTown’s seal of approval):

And here are two examples of Goodby’s creatives–Comcast’s Slowskys and Robert Goulet for Emerald Nuts:

Of course, just by bidding a few dollars more or not or walking away even, the software giant could sass things up a bit, as could an actual Yahoo alternative to what most agree will be its ultimate fate: Becoming Microsoft’s Silicon Valley satellite office, anti-Google division.

This kind of slowing down the pace to approximate the mood generated by those two Slowsky turtles who flack for Comcast is, of course, vintage Yahoo, which likes to take its sweet time doing pretty much everything of late.

But one problem with the drag-dragginess is that key talent continues to drift out of the company–witness the recent departure of Bradley Horowitz, who played the role of the entrepreneur’s best friend at Yahoo well.

While Horowitz is high-profile, I can tell you by the emails I am getting daily from Yahoos that a lot of them are contemplating the door.

That’s why, sources tell BoomTown, that Yahoo is preparing to hand out attractive retention packages for key talent, in order to hold onto them through this process, which would be especially important if Yahoo (YHOO) escapes Microsoft’s (MSFT) embrace.

It’s a prudent idea, of course, given Yahoo has to work hard to keep its current business going with all the takeover distractions surrounding it.

But, more interesting, sources said Yahoo’s plans also include even more juicy severance deals upon a change in control that would give some employees a nice cushion on the way out, either via Microsoft cuts or on their own volition. (Yahoo, by the way, said last week it would incur up to $25 million in charges related to its recent layoffs.)

In fact, upping the severance for current employees is exactly what Dow Jones (owner of this site) did right before the News Corp. (NWS) bid was accepted, handing over enhanced severance packages to 160 senior managers, in the event they were forced out after an acquisition.

In its government filings in June of 2007, Dow Jones said it did so because it “intended to enhance the company’s ability to retain and attract management-level employees.”

At the time, although Dow Jones said such a move was unrelated to any sale, many saw that move as a sign that it was getting ready for it. And, in fact, the company reached an agreement to be sold within 30 days.

So, even at a turtle’s pace, it might be a good idea, in Yahoo’s case, to follow the money.