The problem is, what White hasn't figured out is that a heel champ only works if you have a face challenger to take him down, and frankly there are no heavyweights in the UFC who are going to be a threat to Lesnar unless he gets lazy. He already beat up Couture. If he could handle Mir as easily as he did Noguera won't be any tougher for him to man-handle. Tim Sylvia could match his size but Lesnar's raw athleticism would make it no contest at all.
There's really only one heavyweight in MMA right now who could hang with Lesnar, and he's not even in the UFC yet. But he's got the size, strength, athleticism, speed and wrestling background to match and neutralize Lesnar's best weapons, and I can see the two of them having a series of wars than would make the Couture-Liddell trilogy look like undercard stuff. (Of course they could also have one bad fight where neither of them can ground 'n' pound effectively and they can't figure out anything else to try...)
That guy, of course, is Bobby Lashley.
How weird is it going to be for UFC fans to see two ex-WWE guys as the two most dominant heavyweight MMA fighters in the world?