Thanks a lot for all the comments.
BacE, this was a single deal. No other projects for now, though I'd like to. It was fun.
3dEroticer: For 2d morphing, the usual: After Effects Cs3 and lots of patience. One layer for each boob.
For 3d boobs, 3d Studio Max 2009, flex for the basic dynamics, photoshop and reference frames for the texture, frame by frame animation, lots of tweaks and lots of patience.