The V6 will be the 3.7 pushing 280 plus hp. Many of the in the know people on several boards swear the 5.0 will come with no less than 400hp, with SE's in the 450 range.
Yes a 6spd auto and manual is included. The problem is what is this going to cost? Will we see GT's in the high 30's pushing 40K like the SS and R/T? Also a rumor IRS will be introduced in '13.