Started up MW3, and had to update last night (I play every night so this is the very latest update). This update corrupted my game setup. Symptoms were couldn't find a match, searching for available games would stall at 50.9%. We have 2 PS3's in the house and the update killed them both.
The solution was to delete the save game data and do the update again. Whew. Also I'm having to re-download some of the DLC. Terminal seemed to come with the update, Thought I'd post this in case others ran into it.