If this kinda stuff floats your boat, you might want to check out the ‘Engineering Windows 7’ blog. Pretty interesting stuff about how and why the Windows 7 team has done things the way they’ve done them – for better or for worse.
Also, it really feels like the Win7 team is listening to their users – something that some other companies out there don’t seem to do too well. I won’t name names 🙂
Enjoyable reading, and not too technical. Honestly.
Y.I.P.C.A.N.J.O 
Why listen to your users when you have the best product out there? 😉