Since every piece of software must use the CPU, hardware accelerated video is almost always taken to mean GPU or DSP acceleration.
Originally Posted by izzeho
In the case of ARM chips like those on the Touchpad, the CPU, GPU and DSP share the same die, meaning they're on the same bit of silicon. Even though it's just one chip, they are each discrete components from a programming standpoint. That one chip is not called the CPU, it's called the SoC - System on a Chip.
As such, the only Touchpad video player with hardware acceleration is the one that ships from HP. (as far as I know).
All that said, I agree that it would be great to have a hardware accelerated video player that supported at least 2 or 3 more video codecs. Unfortunately, the API's cannot allow such a thing. Any new hardware video support would require coding specifically for the Qualcom hardware, perhaps even a new kernal.