Source: The Wrestling Observer
As we have been noted since yesterday, Brock Lesnar has been negotiating with WWE for a surprise return at Sunday's WrestleMania 28 event. It has been noted that both sides have been in talks for a month and that WWE at least initially wanted his return match to take place at SummerSlam on August 19. The Rock is aware of Lesnar's negotiations, which is why he refused to say anything to a reporter earlier in the week when questioned about Brock.
Also, Lesnar has arrived in Miami. He arrived with security and a large group of people shielding him from everyone. While not confirmed, the story making the rounds is that he has signed a one-year deal with WWE and will work a schedule more than the Undertaker would work, but less than Goldberg worked for the company.