Apparently it is only playing before digital presentations and if the theater decides to play it.
I saw it last night before seeing Up in 3D and I was quite happy I got to see it.
This is true as far as I know. We only received a 3D version of it, so I couldn't put it on another movie if I wanted to, unless I fixed the Z-screen in place for the 3D-enabled auditoriums and made people wear 3D classes just for the trailer. lol