So, if I understand correctly, you want to put a 2011 V6 in a 2010...unless you just happen to have the engine lying around free, I can't see how this would be practical. Buying the engine and whatever else would be necessary to convert it would probably cost as much as the hit you would take trading the 2010 on a new 2011. Plus, with the engine swap you just flushed your warranty down the drain.
The new engines are mated to 6 speed transmissions. Are you dealing with a manual or auto? I would say the swap you are describing with an automatic would be very problematic at best. With a manual, it might work. Not sure if the bell housings match or not.
Can you explain what you hope to gain with this swap, and tell people a little more about what car you are working with?
2011 Performance White GT Premium
Everything but the kitchen sink...and glass roof
Only waiting since June, so no complaints YET