I'm using the final version of Windows 7 and everything works fine. I believe the drivers are built into windows 7, but I installed the HP drivers in compatibility mode and they work without a hitch. Same applies to QImage.
I'll try installing the full HP driver from their web site tonight. I still can't see the ICM choice no matter what I try with the driver that came with W7 RC 64. I have W7 32 on a couple of laptops, and I didn't have a problem with the canned HP drivers.
Overall, I have almost no complaints with W7. This is the only h/w problem I have at the moment, and I'm sure it's fixable. I have had no problems with any of the Adobe apps, DxO, QImage, etc. I have some old pre-XP programs that don't run completely, which all ran ok under Vista 32 bit. But none of them are particularly important.
I'm using a little Acer netbook as my field machine right now, and it runs Adobe apps on W7 with no problem.