Jack,
The new Pioneer will probably be the PRO710, to compliment their new PRO510 and 610. Yes there will be outboard HD inputs for different kinds of dtv set top converters, but there will still be that HD slot in the back for Pioneer's own HD set top box.
As far as i know, the picture quality is the same, but there some different menu options.. ie. a 72 point convergence system verses a 9 point system on the PRO700. That's not a real big deal anyways because i'm sure that you are going to have an ISF personnel come and set up your picture for you.
The PRO700 has not been discontinued yet until the PRO710 hits the market. If you are interested, I can email you or give you a call when the PRO700 goes discontinued. I can get you a great price on the unit.

John