Borderlands 2 has confirmed this while talking to OPS Magazine about Sir Hammerlock's Big Game Hunt DLC that just came out. "We do have [a level cap raise] planned, and it will be for quite a few levels which will allow you play for quite a bit longer. We also have a plan for Q1."

The timing for the cap raise is partially dictated by Borderlands 2's stat tracking. "SHiFT allows us to see a lot more about the way players are playing the game, and see what they're doing," says Lopez. "We wanted to give people enough time to get at least one level 50 in there, and then see from there."

So there are at least a few level cap raises planned for Borderlands 2. The first is planned to be out by the end of March with subsequent cap raises to come out later as the game needs it.