It wouldn't surprise me at all. I think they are going to be forced to move into smaller displacements. GM has said as much in several places. The summary of which is, its all about performance...not so much how they do it. You will get some blow back by purist...but ultimately if it performs like a Corvette, I personally don't care what it has in it. Look what Nissan is doing with a V6, 538 HP and 0-60 in under 3 seconds.
I have said all along, the new Z/28 should have a small displacement configuration, like the 3.6 DI with Twin Turbos. It would be exotic for GM, just like the 1st Gen Z's were. Ever see a 69 Z/28 with a Cross Ram Intake? GM will likely park one next to the new Z when it is unveiled with a Twin Turbo V6!
Now, I'm ducking from the flame throwers!
ZL1213 (formerly Z OHHH 6)
2010 2SS/RS (Auto/L99)
2012 ZL1 #213 - M6, Black on Black