I think prochembro's probably pretty close.
Lose the optical drive and it becomes a macbook air. Ivy Bridge brings USB3 (finally?) for 'free,' so why not?
A move to IPS or variant also makes sense, although I think most IPS panels use more power.
Ivy bridge will be another step down on the process size to 22nm, which reduces heat, offset by whatever jumps in speed are offered, probably at rough parity with heat vs todays MBPs overall. PCI3 comes into play, doubling the data rate per PCI lane..nice. A second thunderbolt port would be goodness, and it will be interesting to see if they finally implement it as a fiber connection or not, but I'm not expecting it.
Most of the above is all goodness for users.
The bad? A move to SSD. Why?
Look at the Air - soldered on RAM. Apple really loves and has become quite good at managing to get ongoing annual income from it's customers - yearly OS update, MobileMe (I started a trial years ago, and somehow use it as a primary mail account years later, while using virtually nothing else, heh! Nice $100/year for an email account. :-/ ), even silly things you'd get from other manufacturers - like a way to connect your laptop to an external display without a $2, err, $30 adapter. So, let it play out a bit - maybe they push the whole 'disposable' model and solder on RAM, or make the SSD cheap(er) but not user upgradeable - they can drop some $, but so much for those of us who upgrade their machines themselves, want to drop in an optibay, and keep their systems for a few years or more.
Without user serviceable RAM and/or SSD, they just might use the extra space to add decent heatsinks into the MBP, along with, of course, a bigger battery. Need more space? Here comes iCloud - storage on demand. Why do you 'need' a big HD, when for a modest fee, Apple will keep everything in the cloud for you - music, movies, and now - all your files.
I bet they'll be screamers and be nice pieces of engineering, but it's likely going to piss off everyone looking at Optibays or wanting a real 'desktop replacement' type system. I do hope I'm wrong on that, and maybe they'll keep a 'thick, user serviceable model' around for another generation or so, but I'm betting they're thinking the sooner they can turn the laptops into an iPhone/iPad type model with much greater than 50% upgrade numbers within a few to 6 months of each semi-frequent release, the sooner they might be rolling in more extra cash.
Something different that I don't think we're quite ready for yet is simply buy your display - pick the size with integrated GPU and perhaps ARM, solid state drive/flash - there's your 'big iPad,' then buy a 'docking station' with beefier CPU(s), keyboard, Thunderbolt connection in the 'dock' and have the 'docking station' take over CPU duties along with discrete GPU if you've bought the 'Pro' station....at first you'd think it might cannibalize iPad sales, but if the iPad 3 (maybe 4?) can use the same 'docking station,' you've effectively got people buying the 'small' iPad for normal tablet/convenience use, plus 'docking station'/'real' computer plus an additional larger 'iPad' for the screen = $$$.
There's lots of 'coolness' factor in any of the scenarios, but likely alienating some of the real 'pro' users out there. And of course, with municipal broadband (read - unlimited, cheaper, faster in many cases) offerings being shut down by politicians and corporations, and those corps all drooling over the thought of bandwidth caps, it will be interesting to see how Apple pushes iCloud in the future. We have your data and you can get it any time, too bad your ISP will charge you $$$ when you want it too frequently. Unless of course, Apple 'partners' like they did with their phones - 4G/LTE at $100/month or so, unlimited for a year or so, then they pull an ATT and cap it down the road. 😱 Ok, hopefully that one's at least 2 generations away, but we'll see. 😀