Battlefield 4 has yet to be properly, publicly announced. We know it's coming, because it's a sure bet EA will make more Battlefield games and because people already know they're in beta, but nobody has seen the game in action or knows anything about it.
Unless you work for GameStop, because you got to see the game this week. The above tweet says it all, but the fact EA's official Origin account retweeted it says even more.
Given the timing of the tease, I'd be shocked—shocked I say—if Battlefield 4 did not form part of Sony's big PS4 reveal tomorrow.