Yeah well Tony is Sitting on the most important technological discovery ever. Not the miniaturization of the Arc Reactor, but inertial dampeners. By all rights after being shot out of the air in Iron Man 1 by the Tank he should have died on impact with the ground. Just because you stuff something Fragile into something durable doesn't change the laws of physics.
The point is that Tony stumbled into Thor, Thor held back, and even then Tony was barely competitive. But that isn't comparable because we're talking about a Batman who, again if rumours are true, had TWO YEARS of prep-time where he was probably studying Superman around the clock and analysing his every weakness/fighting techniques etc.
And judging by the trailer, Batman's goal is similar to Vanko's in Iron Man 2. He wants to show the world Superman isn't a God and that he can be hurt. Because deep down Bruce is still a scared little boy, and he needs time to work out the fact that he's scared shitless of a world with Aliens.
Ya know, it's like Iron Man 3... only he doesn't shrug off PTSD.