I don't think it's that easy to lay down aces, unless player A has a definite read on how player B plays his monsters. I mean, if player B is sucky, and he pushes a 2cJhTh flop, he's probably gonna have to call that.. player B might very well push there with a meriad of drawing hands. Or drag it out to the turn or river and push there. Player A will be most likely building the pot.

If player B would have had a hand like KK, QQ, AK etc, the situation would be very different. But right now, either he makes his set on the flop (11%), or he's probably dropping the hand (89%). Maybe a bluff on the flop, but that's it.

And player A, due to his hand, and like I said before, will be very hard-pressed to get away from it, lest the board become insanely scary such as a 789T all clubs (with no Ac in his hand). On a normal board, player B might very be going allin with TP or overpair.

But it depends on a lot of factors.. so many in fact that I can't make any definite calculations about who would come out on top. Probably player A though.