In the last post I spitted over HP for not supplying Vista drivers for one of their scanners I own. I won't repeat my disappointment again, rather I'll supply a solution. No, it is not buying a newer scanner from HP.
It is far easier - use [VMWare] Workstation 6.0 (currently in beta) that supports USB 2.0 devices. I tested and it works almost flawlessly. The only trick is that you have to attach USB device during Windows XP (yes, the guest is XP SP2) boot process - otherwise guest machine will freeze for some reason (it is in beta, so it is normal to have bugs). Also I am not sure whether USB 2.0 is supported in their free [VMWare] Player product.
It turns out that [VMWare] Workstation 6.0 is a very valuable solution for Vista upgrade situation, too (besides the obvious advantages) as you can use not supported USB 2.0 devices (and perhaps others) within a virtual machine hosted on Vista.