There are two distinct possibilities, one where it is badged as a Corvette, and one where it is not. If they badge it as a corvette, it will be somewhat conventional in its engine choice. It will be Mid engine rear wheel drive, with An improved version of the Z06 engine, making probably 700+ hp. It will be badged as the New ZR1 ,or the ZoRa1 if they are feeling adventurous (probably not).
Now, the second possibility is where my prediction gets bold, stuff of dreams really. It will be a entirely new nameplate, Like Zora, and it will have a Hybrid electric system with batteries derived from the Volt. The engine here doesn't need to be a V8, as it isn't a Corvette, so a turbo V6 is possible, probably a hopped up CTS Vsport engine. Its going to basically be a NSX/ GT competitor, and it will be amazing.
We will probably see it at next years Detroit autoshow, so much more may be reveled by then.