Read post 766. I'd say the answer is most definitely yes. HPB is in the works.
As far as a comparison of HP1 & 2's official extended releases versus ADM's cut, it's mixed. There are a few transitional elements, and some slight differences in order on the official versions.
On the down side, IIRC there are some continuity problems and sloppiness to the additions in the official cuts that ADM smoothed out.
Just to be clear, there are only official extended cuts of the first two films. ADM's edits are still indispensable.