It looks like Windows PE can be used more then just to install Windows NT 6+ (Vista/2008/7/2008R2) or as a recovery console.

Installing Windows NT 6.x from USB is almost as easy as installing from a DVD.

When I first bought my Asus Eee PC 901 it was a headache to install Windows XP on it. But soon I found a way to solve that.

I installed both Windows 7 Beta and Windows 7 RC1 with UNetBootin (with a little tweak). I was successful to boot WinPE 2, WinPE 2.1 and WinRE 3 RC1 with UNetBootin. I would guess Windows 7 RTM will have no problem either.