Well, I have to come out here and say I like the Microsoft / Seinfeld ad. I think it's funny ... and non-obvious. I'm not sure where they're going, but at least in this sphere they don't seem to be trying to catch up with Apple.
Weird though that now they try to make Bill Gates a brand-mascot, now he's left.
Update : Second thought ... the total lack of any kind of real "message" (apart from "Gates wants to be seen as a fun guy and hang out with Seinfeld", obviously) may be making a virtue of necessity in that M$ don't actually have a message at the moment.
That's perhaps not a bad position to be in ... maybe the first task has to be to destroy our previous perception of M$. And that means reinventing Gates as no longer the mega-rich, evil, world-dominating manipulator behind the scenes but a lovable, fun, nerd who still buys discount shoes and jokes around in an archly subtle way. (From his performance here, Gates could actually be made into a pretty funny comic actor. Couldn't you see him cameoing in a Woody Allen movie?)
M$, if anything, are the practical, pragmatic choice of conservative IT departments. What if you could pull off the antithesis, upping the nihilism in the Microsoft ads, to make Apple (in its race to the enterprise) look the stodgy "sensible" choice, while M$ discover an entirely clean space to reinvent themselves as whatever they want to be seen as next?