I just don't see Lashley beating Lesnar.
Lashley has looked good in his fights, but they wern't anything to get excited about. He hasn't faced a big name in their prime, or in fact a big name that's still got something to offer. Compare that to Lesnar, he killed Mir before a rookie mistake. He tonked Mir last night, and he can take hits too. He took a huge knee to the head, but still stuck with it and then knocked the shit out of Mir.
If Lashley got the UFC training, the high level, he'd be very good. But if I'm being honest, I don't even see him beating Frank Mir. I don't see Lashley being as technically sound as you need to be, to be a champion. I just think Mir would murder Lashley there, so what hope does Lashley have against Lesnar? His technical skills have improved drastically. He's much more aware of his game plan.
Unless Lashley gets some big wins under his belt, he wouldn't even earn the right to think about fighting Lesnar. IF Lashley can beat Mir & Corture, then I'll think about it. Even then, Lesnar would tonk Lashley out within the first round.