For Microsoft, I can totally see the logic. Their own search technology is miles behind that of Google. Allegedly, one of the drivers behind Longhorn's WinFS was Gate's observation that Google can search the Internet faster than Windows can search your C:\ drive. I don't know if the quote is even close to being accurately ascribed - but it's underlying truth is indisputable.
At the PDC I got to meet some of the people at Google. They are a lot like the good folks at Microsoft - open,fun, and with a great work real hard play even harder mentality. Everything I see is simple, clean and with an incredible underlying elegance - which is everything that Windows is NOT. Don't get me wrong, Windows is an outstanding OS, but it's hardly simple (if it were, I'd not be in business!). It's far from clean, with way too much eye candy and it's hardly likely to win an award from Weight Watchers. While parts of Windows are truly breathtaking, there are too many elegant hacks - things done in the name of performance and there are far too many inconsistencies (how you load/activate/remove components, etc, etc, etc). I suppose this why I'm so in love with Monad - a simple, elegant concept.
But back to Google - if they get bought, their folks would have to change. I mean, you couldn't have the lava lights in the offices (just think of the possible litigation from an employee who gets burnt). And those silly updates to the google's logo.gif on their homepage would have to stop, since they might offend someone somewhere somehow and we just couldn't take the risk. The cool clean look of www.google.com would have to change to more closely resemble www.microsoft.com. (By way of checking the google.com home page is a mere 12.9kb of data, while www.microsoft.com's home page is nearly 140kb). And finally, how long do you think they'd be allowed to run Linux?
As I see it, Google is still fun - a fun to work at, fun to use, and fun to watch grow. Whereas, Microsoft almost by necessity, has had to become all too corporate. Sure it does cool and fun things, but at the same time, it acts ruthlessly when it has too. While I can certainly see the logic in Microsoft buying them, and the potential benefit to millions of Microsoft customers, I guess I'd hate to lose the fun.