The only way this could ever happen is if Brock Lesnar decides that after the stomach illness/surgery/recovery that he had, he simply isn't at the level he needs to be in UFC. Lets be honest, Some UFC refs would have stopped the Carwin fight in the 1st round too. Truth be told, I think he has lost something since the stomach problems. He isn't the same fighter. There are three things that have to happen for this to even be a possibility:
1a. Brock Lesnar decides that he if can't compete at the highest levels in UFC, he isn't going to compete at all, and decides to retire from MMA competition. I would put these odds somewhere around 20%. Not very likely, but given how his last two fights have gone, the idea cannot be completely dismissed either. If this happens, see 2.
or
1b. Brock Lesnar obtains permission from the UFC to make a few WWE related appearances, and compete in a single wrestling match at Wrestlemania. This would not require Brock Lesnar to give up MMA competition. However, given that Dana White has said that while under contract with the UFC, there will be NO outside competing, I would put the odds of Dana White changing his stance on this to be around 5%. Vince could make him a cash offer that makes it worth his while to give permission, I guess...not bloody likely though. However, in the incredibly unlikely situation that 1b actually happens, skip directly to 3.
2. Upon his decision to retire from MMA competition, Dana White agrees to let Brock Lesnar out of his contract. This must happen, because legally, Brock cannot do ANY sort of outside competition without permission. Even if Brock Lesnar retires from the UFC, Dana White could simply not release him from his contract. Assuming Brock decides to retire, the odds Dana White would let him completely out of his contract, no catches: 0%. Brock is a money maker, Dana White knows he is a money maker, and isn't dumb enough to let him off without any strings attached. There would have to be some form of no-compete clause that would allow Brock to return to pro wrestling, but not to sign with any MMA organization. Assuming that Brock does retire, odds that Dana White lets him out of his contract with some form of a no-compete clause, instead of making him sit the rest of his contract out: 70%. I would think that should Lesnar retire from the UFC, that Dana White would probably be accomodating. I don't think he would be petty enough to refuse to let him out of his contract, provided he couldn't hurt the UFC by signing with a rival company. Again, this is under the assumption that the scenario outlined in 1a actually happens, as unlikely as it is.
Before I get to the third thing that must happen, I have to point out that my entire post is entirely dependent on Brock Lesnar choosing to return to pro wrestling. He could decide to retire and not return to the WWE at all. Even if he retires, even if he gets let out of his contract, even if there is a no-compete clause, we don't know if Brock Lesnar even would consider going back to the WWE.
3. Assuming Brock retires, gets permission, or is otherwise available, both himself and the Undertaker have to be healthy enough to have a match. This is probably the only time in his entire career that Mark Calloway has to wonder if he is going to even make it to Mania. I know it seems impossible, but with the collection of injuries, its possible that by March 2011, the Undertaker is either injured and cannot compete, or not even in the WWE at all. The Undertaker has a slew of injuries that aren't getting any better. Combine that with the fact that he just put Kane over in a match that 90% of the WWE audience expected him to win, it could mean that Taker is on the way out, and is legitimizing Kane's title by losing. Its purely speculative, but, a case could be made to suggest that Mark Calloway's career as a professional wrestler is virtually over. Odds that Undertaker is capable of competing in a match against Brock Lesnar at Wrestlemania: 40%. This is the first year I really have had ANY doubts about the Undertaker, but the doubts I have are big enough for me to recognize that at his age, with the injuries he has, whether or not he stays healthy until late March is a complete crapshoot.
When you look at everything that has to happen in order for this match to come to fruition, I just don't see it happening. Too many unlikely things have to happen. It would probably be epic, but, its just a pipe dream.
