Theoretically you could combine an XMLTV data source with a VDR/MythTV/Freevo/video archive to use XMLTV as an index in some new format.

What'd be better, given VDR/MythTV/Freevo/video archives have additional meta-data anyway is expose a listing of those in some HTTP-based XML protocol, possibly RSS. This could well be the "Internet TV" that's mentioned in VideoCenter.

It'd still need a transcoding solution at the backend, though.

With some more information on what these data sources in VideoCenter are, however, it could be very possible to use VideoCenter as the tablet-based UI to an on-demand transcoding solution, using something like 770-encode at the backend.

Very simple (and powerful) indeed... hmm.