There is a 17inch MacBook Air coming out?
Nobody knows. And an air isn't what you want seeing as you're doing higher end rendering and processing.
I don't think that's been confirmed at all yet. Like most things on this site, it's a rumor. If you need a computer now, buy it now. If you can and want to, wait to see what comes out in the near future.
This.
But to just insert my opinion, you're going to college. I'm sure by now (hopefully) you know the importance of reading. That holds true to forums. Take maybe 2 or 3 days and READ the posts and topics that are already here.
There are a plethora of people who come here and ask for advice about things they can simply answer themselves. It doesn't take much time, nor effort, to sit down, open up 3 or so threads at a time, and read through them.
When buying ANYTHING, you should be edudcated on the subject. From cars to homes to electronics; the WORST thing you can do is go to the dealership/best buy and ask someone there. THE WORST. Coming to a forum is a step up but the BEST thing you can do, in any situation, is read.
Get to the point where you know about everything (in this case, all of the MBs and how "good" they are) so you can simply stop, think for a minute or two, maybe make a bullet point list, and then decide.
Coming here asking between the Mac Pro or a MBP is great; you can simply decide between the two if you're going to have to move the thing. Since you already have a MBP you can simply search for benchmarks and then decide for either/or. That's the smartest and easiest thing to do; AND you would have already known the answer by now.
I don't' mean to get off the soap box, but if more people in general actually did put effort into learning/reading before buying, half of us wouldn't be posting mindless topics here on the forum (not saying yours is, just in general.)
You're going to (or in college). You should already know this first hand. I'm only 19 and I knew this a year ago at least.