The Carrera 4 is coming this autumn, we just got this in from a reliable source. Rennteamers actually knew it before, right?!
Right now it seems that the Carrera 4 gets the 355 HP 3.8 l engine and a slightly wider body with some little differences in the front part too.
The Carrera 4 S is rumoured to get the 380/381 HP 3.8 l "powerkit engine", body width is the same as with the Carrera 4.
We don't have any information about a Cab version yet.

Again: the Carrera 4 is practically "confirmed", the Carrera 4 S is still a rumour but a pretty strong one.