I'm told Vince McMahon was aware that Brock Lesnar would be at UFC 146 in Las Vegas last night. Otherwise, the feeling is there would have already been a lawsuit against them in place for using his likeness on pay-per-view. While one source commented about how well this would have looked had this been done on purpose to sell Lesnar "quitting" WWE, it's believed it just worked out where it looked that way as I'm told "no one" thinks that far ahead in booking and it just worked out that well.
As for Lesnar appearing and Dana White talking about him wanting to fight again, I'm told it's a possibility that McMahon could OK a fight between Brock and Frank Mir at the end of the summer. This way, if Brock were injured in the bout he would still be able to compete at Wrestlemania next year. There is also a possibility this is just a ploy to draw buzz.
One observer in the know feels like Vince wouldn't OK Brock fighting again because if he lost, he would no longer look dominate. Remember, Vince wouldn't allow Kurt Angle to tryout for the Olympics because he felt the silver medal didn't matter and ultimately made him look worse.
All and all Lesnar's appearance last night appears to be nothing more than him generating a buzz for himself, UFC and WWE. Perhaps the most interesting thing to come out of it is WWE Champion CM Punk now feels like he should be allowed to appear with Chael Sonnen. It will be very interesting to see if what happened last night makes that a reality or if Punk goes out on his own and does it anyways.