From what you have said so far there may or may not be OW involved no for sure. He sounds like he may be depressed and maybe he thinks moving out will make whatever his problems are desappear. It is hard telling try not to spend to much effort figuring him out, afterall he may not even understand himself at this point so how are you suppost to.
Me - 34 W - 33 S - 5 D - 4 M - 14 years Bomb 1 Dec 06 Bomb 2 Aug 07 Separated - Aug 07 WAW Renting own place - Dec 07