Correct, I've got a Core i5 2500k for gaming/encoding duties. The AMD would be purely for playback. I'm just trying to decide whether to go with the cheaper Penitiums or not and forgo the discrete card..whether or not that the HD Graphics can handle everything HTPC playback related..
The Trinity IGP is more powerful than any Intel HD Graphics. For an HTPC the AMD A series should stream HD movies, videos and games at low-medium settings with no problem.
Because is an HTPC I don't think you're going to do encoding or compressing files but in that case an i3 or i5 is much better.