Interesting problem. According to the release documentation, you should be able to apply shape keys to “Meshes, Curves, Lattices and Surfaces” easily. However, I don’t see a Shapes panel in the EditButtons (F9) for anything but Meshes. When pressing IKEY, there’s an option for Curve (or Lattice or Surface) just like there’s one for Mesh… but nothing shows up in the Shape IPO window.
Is anyone else running into this? Is this a bug in Blender or the documentation, or am I missing a step somewhere? I’m running a CVS checkout that I did today.