Plenty of problems with MLB.TV, but if you don't get the games locally, its the only way to go. One problem is that if the game IS local, they will black it out, even if you want the visiting team's feed (nothing worse than listening to a damn home-team announcer for your rivals).
Even worse about blackouts are that even if you have the premium package which allows access to archived games, blacked-out games aren't available until 90 minutes AFTER the game. It's bad enough they blacked you out, but for some reason you can't even watch a recording of the game for 90 minutes, as some sort of punishment.
However, since I used a New Mexico credit card, nothing gets blacked-out. Sometimes the Southwest has its benefits, and other times you get stuck watching Cowboys games (blech).