I think he originally intended for the new features to be made publicly available, hence the take-down of beta12.

(That's assuming it was the exact same beta12 that I've got which doesn't have those new features-- the release notes are in error for the beta12 that was released to the alpha team.)

So I think he's going to try and cobble something newer together and see if it works (I hope anyway), and release that if it does. I'm guessing it'll be labeled beta13 or later when all is said and done.