I couldn't find any topic yet for mythtv client for N900 and Maemo 5.

There was previously a working version for Diablo
https://garage.maemo.org/projects/mtv/ but it lost development activity but was already a very usable. As mythtv is also based on Qt it would easy to port and probably already done but it should also include a feature for streaming and encoding to proper resolution so that you could watch live or recorded videos, listen music etc remotely and even through 3g connections from home.

Anyone else interested?