Call me an old cynicalboots if you will, but I would be very surprised if the prototype TX-SR607 on show with Dolby at CES is much more than a TX-SR606 with some cosmetic changes to reflect its new model number and PLIIz implementation, or simply a mock-up.
Given how jumpy Onkyo got last time we revealed their new products earlier than they wanted, I'd be very surprised if they've let any cats out of the corporate bag this early in the year.