I'm guessing revamp: Penryn, minor graphics card change (maybe), and a case revamp. For the case, I'm not expecting it to look all that different externally, but I would expect it to be completely aluminum, like the ipod classics, with the new style keyboard, magnetic latch, user accessible hard drive, and probably a black rim around the screen, like on the new imacs.
I'm expecting an ultraportable MBP as part of the case revamp, if only because Apple doesn't have anything else new and exciting to get people excited about. I'm hoping it's a tablet, with multitouch, but I don't expect that.