How would I animate a transforming blob?

Looking for how to do something to the effect of near the end of this video http://www.youtube.com/watch?v=WGvXCXtPofI, where the mess of cubes seem to transform smoothly into a perfect sphere. Specifically, I’d like to form a blob into a human, but what would/could be the basic method of doing the cube-to-sphere? There’s no mesh-tween type of thing, right?

This would be something done in real time too.

perhaps animate forming the blob into a rough human shape, have another human mesh actually made up and in another layer, then do an “alpha over” node in the compositor to do a fade from the blob-human like shape into the actual human mesh.

Just my thoughts, will take alot of work though!!