To be fair Win7 has some nice features but let's not forget it's still huge, full of nannying and hides options in obscure places, splatters DLLs all over your harddrive and eats resources. In short, it's still Windows. To the credit of Apple, at least they have been trying to trim the resource footprint of MacOS. MS could do with following suite.
I agree with the comment on 64bit being a missed chance for MS to go this direction. Let's face it, over 200Mb for a driver! That's insane.