"There would also be tax breaks for consumers buying plug-in hybrid cars" House Passes Renewable Tax Credit Bill House Passes Renewable Tax Credit Bill
You'd have to talk to your rep. but I suspect a plugin Prius would fall under the same classification as the current Prius. That is, enough vehicles have been sold so the vehicle no longer qualifies.
I think you are correct; however, the rebate was tied to the number of hybrid vehicles sold by the company (Toyota). Toyota could invent new types of hybrid cars but, as a whole, Toyota had sold the maximum number of vehicles available for a rebate and a limited rebate. No Toyota vehicles will get a rebate unless the legislation raises the maximum number for the rebate. They probably won't do that because they would have to re-do all the folks that received a partial rebate this last year.