-- Brock Lesnar's contract with WWE expires after WrestleMania but he would still have some committments with the company keeping him around through August. If he leaves after the summer to return to UFC, the talked about program with Bobby Lashley obviously won't be happening and it appears the only way he might want to go back to UFC is for a big payday in a fight against Jon Jones.
-- Ultimately, Lesnar might do the same thing he did last time his contract expires - use UFC as leverage to get a better deal with WWE. Even if he leaves WWE for a fight or two in UFC, most believe it is inevitable that given his age, he will eventually be back to wrestling at some point in the future.
Source: Wrestling Observer Newsletter. Subscription information & prices available at f4wonline.com