I purchased the Sony CDX GT710. I have XA30 UniLink Source Splitter hooked to a trunk mounted CD Changer and the Phat Box. I did a quick check at lunch and replaced the old head unit with a Brand new CDX GT710. The unit functions and interfaces with the Phat Box perfectly.
So far it appears as though nothing has changed in the protocol and the New Sony Head Units with Uni Link are compatible.