One of the most-requested fixes we receive for the game is to adjust the balance of characters - especially those that are dominant in Versus. While I think most dedicated players knew the Ragnarok re-balance was coming, I suspect many aren't sure what's next in our efforts to make all characters useful. We're well aware that you work hard to level up characters and to that end we wanted to share our current priority for re-balance. In order, starting from soonest:
Invisible Woman (Classic)
Thor (Marvel NOW!)
Wolverine (Astonishing X-Men)
Please keep in mind, that we are constantly finding new and interesting ways to use the characters in the game and we may insert changes to this list. Going forward, we'll do our best to keep you aware of our ongoing plans to keep the game tuned well.