Everybody played the same waiting game with the Dell Zino, but at the end of the day, it didn't support bitstreaming of Dolby TrueHD or DTS-HD. I assume the Zino supports 24p properly, but I've lost track of it.
The Engadget article says that the Asrock will have an Intel Core mobile processor and a NVIDIA GeForce GPU. Intel Core mobile does not necessarily mean Core i3, so bistreaming is not a given. According to this
, the current NVIDIA GeForce GPUs don't bitstream. I'll put my money on the Asrock not bitstreaming.
Now, if you don't care about bitstreaming Dolby TrueHD or DTS-HD, I'm sure you'll be able to do eight channel LPCM on the Asrock. Of course, you can do that on the Dell Zino today... So,
Dell Zino - available now - no bitstreaming - no Blu-Ray
Asrock Vision 3D - available sometime - probably won't bitstream - should have Blu-Ray
Build Your Own - available now - bitstreams - has Blu-Ray