This is what i've found on other forum
General Motors are currently looking to meet the new emissions regulations, while trying to save the Corvette. The rumors of a rear mid-engine Corvcette are false, the C7 will be the first of a mid-engine Corvette alright, FRONT Mid-engine and powered by a rumored 5.0 liter supercharged V-8 or a new turbocharged 4.9 liter V-8, either way look for some real performence form a Corvette that will be lighter then the current car, as well as more compat thanks to smaller components!!!
The Corvette may get a race bred 4.9 liter V-8 fitted with a supercharger, producing around 450 BHP in the base model, and tuned to 600 for the ZR1 successor. The cars body will be smaller to showcase it's new power to weight ratio, the Corvette Centennial Conept will show alot of new themes for the C7.
http://carspyshots.net/showthread.php?t=15028&page=3
Also it seems there will be new engine in corvette for racing.
The new GT Corvette C6.R race car will be based on the production Corvette's chassis and body design. A 6.0-liter version of the LS7.R small-block V-8 will power the Corvette GT2 entry in the transitional 2009 season. A new naturally aspirated 5.5-liter version of the production GM small-block V-8 will be developed to meet the new GT regulations that will take effect in 2010. The chassis and powertrain specifications of the new Corvette GT entry will be submitted to the ACO and FIA for homologation approval.
http://www.americanlemans.com/News/Article.aspx?ID=4783