Let's run that list again:

SQL 2008 R2

Windows 2008 R2

Office 2010

Visual Studio 2010

(Windows 7)

(Exchange 2010)

You have to think about it; that's a big list. I would guess that 1/2 (or more) of the company are engaged in developing and selling those products in some way (design, dev, test, PM, marketing, etc.). I'm wondering if Microsoft hasn't had enough manpower to see a synchronized release of their flagship products until now. Sure, MSFT is a big company but we must be talking tens of millions of man-hours - could even be hundreds of millions - to do a fully synchronized release cycle of this size.

It will be interesting to see if they can do it successfully. It will certainly set the bar very high for future release cycles.