This is pretty cool. I haven't followed graphics tech in a while, but Subdivision Surfaces are one of the most important modeling primitives around. Back in the day when Catmull and Clark first developed them Pixar held a patent on them and it was pretty unclear how aggressive they'd be defending it - the controversial removal of Larry Gritz's BMRT didn't bode well. It's great to see them making steps towards an open model at last.