Google has a conference, well known to all and sundry. Google plans a big reveal. Microsoft plans a big reveal to steal some thunder. Normal PR all around.
But look at the scope of the two reveals. Google essentially plans to reboot the entire mechanism of interpersonal interaction on the internet. Whether it will ever work, catch on, or even be useful it's without question astonishingly ambitious. Arrogant even. "We're so smart we'll tell you how you should be talking to each other." Love, hate, angry blog posts are generated in abundance.
Microsoft launches a new search engine. Which, to be fair, seems like a quite nice new search engine. But where's the ambition? Where's the absolutely insane, balls-out wtf? Even if the Zune was better than the iPod it would be a clone. Even if Bing is better than Google it'll be a clone. Even if the Xbox is better than the Playstation it still won't be qualitatively different. Sure some of them may succeed and none will likely fail completely but it's hard to see the ambition in any of them.