I hate the speculation BUT here goes...
I went to Manassas Subaru today and the salesman I spoke to new all about the new turbo. He said they already have one on order for next spring.
He also said that it will be the 2.0 liter 220 hp spec we heard so much about and the price is 25-30K. This range was dependant upon options! It will also be called the Impreza GT. It will be available only in the four door model as far as he knows.
The only reason I am posting this is because he seemed to be very knowledgeable and was really able to converse well on the 2.5 RS, proving to me that he actually did know his stuff, and was able to answer any question I could come up with on the upcoming turbo model.