If that's not doable, I guess I'll build a new Ion-based box and use xine for output. The problem then is that you don't tend to get many PCI slots for DVB cards (well, not with the small Atom boards). Maybe I could just keep the current vdr box (2.66 MHz P4) and stick an Nvidia graphics card in it. Decisions decisions...
Let your DVB-Cards in your vdr box and stream to the Ion box either by using a vdr instance on both boxes and use streamdev between them, or having only a vdr instance on the ion box and use vtuner to stream directly from the DVB cards on the vdr box to the ion box.
Currently I am testing vtuner on a Seagate Dockstar with 2 sundtek DVB-C USB sticks that is streaming to a Zotac HD-ID 40. It is promising.
Gerald