I'm going to give this one a miss.
Battlefield 3 wasn't terrible, but it failed to keep me interested for too long, and sometimes I just gave up on the multiplayer. I have it on PC and PS3, play it for a week, get tired of it/annoyed, quit it for a few months, see a cool video on Youtube and suddenly I feel like playing it again.
I think they rushed BF4 a little, and it looks identical to 3, so I can't see the point. The game is really expensive right now, and they're going to release a hundred map packs and DLC, when you add it up you end up spending a lot of money on one game. And to make matters worse, if you don't have the DLC, then the game becomes monotonous since it comes with almost no maps at all. People get tired of the original maps and move on to the DLC, but if you don't buy it then you'll be playing alone most of the time.
I'm not saying it's a bad game, but I'm more than satisfied with just replaying BF3 every now and then when I feel like it.