Here’s the info. on the variants for TMNT #2 from IDW.  Available on September 21, 2011.

1. Cover A (Dan Duncan) - regular cover shipped in a 4:1 ratio (A:B) in a single order (i.e., if shops order only 1 copy they get Cover A; if they order 4 copies of Cover A they can then purchase one copy of Cover B)
2. Cover A Newsstand (Dan Duncan) - newsstand edition distributed only to newsstand retailers (primarily Barnes & Noble)
3. Cover B (Walt Simonson) - regular cover shipped in a 4:1 ratio (A:B) in a single order (i.e., shops must order 4 copies of Cover A in order to purchase one copy of Cover B)
4. Cover RI A (Kevin Eastman) - 10 copy Retailer Incentive (i.e., shops that order 8 copies of Cover A and 2 copies of Cover B get this one free)
5. Cover RI B (Fred Hembeck) - 25 copy Retailer Incentive (i.e., shops that order 20 copies of Cover A and 5 copies of Cover B get this one free)
6. Cover RE Jetpack Comics (Peter Laird) - Jetpack Comics Retailer Exclusive Edition; available for purchase at Jetpack Comics
7. Global Conquest (Kevin Eastman) - International Edition issued to markets outside the U.S.A.
8. 2nd printing (Kevin Eastman) - B&W sketch version of the Eastman RI A cover with red lettering; released Oct. 12, 2011
9. 3rd printing (Kevin Eastman) - B&W sketch version of the Eastman RI A cover with bright green lettering; released Nov. 16, 2011