Well, this certainly wasn't unexpected as he gets closer to primaries where he has to appeal to Scary Conservative Base People.
Honestly, too, the thing that bothers me the most is him saying "I'm going to put strict constructionist judges on the bench". That's a blatant appeal to wacko base people and flies in the face of everything he's said he stands for in the past, at least as far as I know.
The whole gay thing is just sad, and in 50 years we'll be looking back at it like people are looking back at the civil rights era and shaking our head at the stupidity of the thing. Personally, I believe that any two people dumb enough to get married deserve to, regardless of gender.