Recording the incoming signal is not the difficult part.  The difficult part is the management.  Scheduling recordings, storing recordings, deconflicting recordings given a variable number of tv tuners, receiving and processing accuarate show scheduling information.  These are non-trivial items which took the MythTV folks a while to get right.  If we're going to go down this route, I think it would make more sense to connect to the MythTV backend (whether remote or on the local machine) and manage recordings that way, but all in due time.

Chris