I feel that 3D works better with Animation films. Such as Megamind,Despicable Me,How to train your Dragon and Monsters vs Aliens. I only saw Megamind in 3D but was told all the others were good in 3D. Although I did see abit of Monster vs Aliens on one of those Sony Bravia 3D TVs. Megamind 3D was nothing short of amazing ! It had me leaning far back into my chair when a long pole came out at me.
What exactly do we expect from a 3D film? We expect to be avoiding things flying out at us from the screen or to have that feeling that we are in the middle of the action. However post-production doesn't deliver this experience. Sad to say but very true. What I'm not saying is that you should never go to watch a 3D film if it's not animation. By all means go and watch any 3D film you like. All I'm saying is that the 3D would be much better if the film was shot in 3D.
So post-production doesn't work. But if a movie was shot in 3D it would be entirely different.
We can only hope that film makers realize this. James Cameron is working on 3D glasses free 3D technology though. Only time will tell how that project will workout.