more importantly, GM wont make the SS the top model any more, if we are lucky. Any car can be an SS, only a camaro can be a Z/28 
Obviously the LS2 or next available variation is a given for the car. There has been soem talk of a base model/top model V8 as well, it worked incredibly well for the 3rd gens, as most people wanted a V8 sound and feel without having the fastest/most expensive offering. And Bob Lutz has already made a comment about an LS7 level car, saying that they ‘have anohter 100+hp available and proven in case the other companies want to get into a power war,’. So while all of the bells and whistles of the LS7 may not be available (dry sump oil, titanium rods, sodium filled valves), there is no reason why the 365cfm cylinder heads couldnt be included later 