Uh-oh. The surest sign that the decline of a tech-power is nigh:
Google is going to build a new HQ.
Or at least they are going to do a massive expansion at NASA in Mountain View, on land next to their current HQ.
This is an old Silicon Valley saw - when companies build giant new facilities, they tend to go downhill soon thereafter. It's a classic "market-top" signal. The litany of examples includes: Apple, Cisco, Intel, 3Com, BEA, Sun, SGI and many others.
And it makes sense - the companies that do this are generally getting too big and prospering in their mid-life. They plan a massive expansion and something happens - maybe the economy slows down, or maybe they lose focus. In any case, building the new HQ is usually done at the peak, and often portends bad times ahead.
Now I'm still bullish on Google, but planning for expansion like this worries more a lot more than anything Microsoft would do.