Meaning of Windows Vista HCL: Driver available as part of ...?

Hello All,

I have a few pieces of hardware which have a Windows logo for compatibility
with XP, but I noticed on the HCL that with each piece of hardware I have
which is not yet certified as working with Vista, the HCL still states:

X86 Driver available as part of Windows Vista
X64 Driver available as part of Windows Vista

I installed a copy of Vista Ultimate 32-bit (I think it is only RC-1, which
I got from Launch 2007 Conference in Seattle, WA) on a separate partition
(dual boot with XP Pro 32-bit) and one piece of hardware could not be
installed (DocuMate 262 scanner), despite the HCL claim that such a driver is
available as part of Windows Vista.

My question:

If the HCL states that all my hardware has an available driver for both
Vista x86 and x64, does that mean my hardware will work with either 32-bit or
64-bit Windows Vista?

If so, I would definitely like to purchase the Vista Ultimate 64-bit.

Thank you,
Edward P. Sager