Are you sure this is right? do you have any links or other info regarding this to confirm/back it up?
With programs such as Arcsoft Total Media Theatre and PowerDVD, the hardware acceleration option is always there and ticked on my 8371 (it's not greyed out like it would be on a system that doesn't support hardware acceleration).
By all accounts the Intel 4500 was pretty much designed for high definition playback and has a high level of hardware acceleration for this purpose as far as I know (
clicky) and I'm almost positive the ATI card will have it also (
clicky).
Granted the drivers need to support it but considering that the hardware came first before the drivers I'd expect even the earliest version of the driver to support the capabilities of both cards.
As far as I'm concerned hardware acceleration is working fine here?