I'm pretty sure there will be a design revision. Mainly because its been a while since they have changed the body style, and Apple has removed the optical drive on everything but the pros yet.
It's pretty safe to assume that they will also remove the CD drive on the next pros. I would not mind if they kept the unibody design it is very efficient since it works as a ground and a heat spread, but if they have something better I aint complaining.
The computer may be thinner or at least lighter. Since they will still use 15in space we may see a larger battery.
Apple still has that thin keyboard, we may be seeing that coming up soon, and then there is also OLED screens, would make the screen even slimmer then the current LED, hopefully save some power there too.
As much as I would like integrated flash, as the air does, the pro is still tailored for a different audience and may keep its hard drive or have a hybrid of integrated flash along with a hard drive, its difficult to tell with pricing and performance.
If they save enough battery life from such cuts, they will be able to allow for less under clocked processors, which means more performance. Those necked 22nm ivy-bridge processors are supposed to be more efficient with their 3D gate design, so we can see a good leap in computational performance
