Hi,
I'm also interested in this topic, although I'm looking for a really *embedded* device: Some newer LCD TV sets are internally based on Linux (yes right!), some even using the DVB API (for the internal DVB-T tuner). I'm currently trying to find out more about the firmware, but I hope it might be possible to run VDR right on a TV...
The devices I'm currently looking at are the Philips PFL97 Series and Sharp's XL2E Series. Sharp looks currently more promising, as the firmware upgrade file is a plain ELF executable, containing a 2.4 kernel with a lot of configured USB options. Philips on the other hand is already using a 2.6 kernel, but I haven't been able to extract anything useful out of the image. (Both kernels are Montavista and source code is available)
Both devices are also MIPS, so maybe we can get something done for the overall architecture.
AFAIK, there is already at least one embedded project working with VDR, namely the Open7x0 community running VDR on Siemens' Gigaset M7x0 boxes (also MIPS based): http://www.open7x0.org/arena/forumdisplay.php?fid=3 (in German)
Best regards, Christian