I now have spoken to VIA Embedded on Facebook, asking about new drivers that support HD playback on the P820 board and the answed I got was:
VIA Embedded yes, we do but we don’t provide chipset driver directly to end users. If you are our customer, please contact with our sales representatives.
On my other question if I was supposed to buy the driver from them to get it to work I got the answer:
You many go to this web site, http://linux.via.com.tw/support/downloadFiles.action
We don’t wanna release it since there are so many Linux version and it’s not quite easy for us to maintain.
With this information I would never ever have bought the moder board from them. This is also discussed at VIAArena. I really hope sone drivers will be released or else I will have to see how good the P820 blends.