I still think that Herring will be able to keep Brock at bay and keep him from getting him on the ground. Herring has a ton of experience, and is quite the bannger on his feet, something that could definitly put Brock away.
Not that I don't like Lesnar, but his chin hasn't been tested, nor has he off his back, and wrestlers do not do well on their backs. If he comes in with a good game plan, and gets Herring on the ground, he could pound it out easily.