Apparently, Mega Man and Roll are seeing a few minor tweaks for the North American version of Tatsunoko vs. Capcom. This information derives from the latest build of the game, which was playable during the EVO 2009 tournament.
7 8 9 = ＼ ↑ ／
4 5 6 = ← N →
1 2 3 = ／ ↓ ＼
Faster air dash
Can combo 2B/5C into 3C!
Still has her OTG combos.
Mega Man Volnutt updates
5A - 5A - 5A - 5B - 5C xx 236+Attack Infinite no longer works.
236+Attack has more delay at the end of the move.
/\ J.C xx 236+C - JC \/ still works.
Full summary available at Shoryuken and Capcom Unity