It will be interesting to see but Lesnar appears to me to be the type of fighter who gives BJJ dudes fits; vicious GNP and the strength to power out of anything. Granted, I am making a lot of assumptions based on one fight.
Maine has a good swing for a pitcher but on anything that moves, he has no chance. And if it's a fastball, it has to be up in the zone. Basically, the pitcher has to hit his bat. - Mike Pelfrey
Poor Mir - it was a no-win situation for him. If he wins it's only b/c he was fighting a pro wrestling guy who was an MMA noob but if he loses he lost to the noob. Even though he won all anyone will remember is him getting overpowered and pummelled on the ground.
Lesnar showed a ton of potential just by being able to toss around Mir so easy. Even though he a wrestler by nature, his ground game has a long long way to go. Using little rabbit punches as a ground & pound strategy will get you nowhere, even if your hands weigh 50lbs each. 6 months of jiujitsu training would go a long way just so he can get a better understanding of body presence. I don;t see him having a problem doing a takedown of Tim Sylvia like everyone else has had so much trouble with in the past.