MBP is easier to future proof since you can upgrade a few components yourself now or a bit down the road. MBA is great for travel, but upgrade options are a bit more limited.
If you still like your 17" MBP and don't mind the size, I would suggest upgrading to a 256 GB SSD and see if that'll suit you. It sounds like you aren't that technical so all the new specs/mumbo jumbo won't really do much for you. With the simple SSD upgrade, I promise your computer will feel like new again. Plus you won't have to bring the desktop to college either.
I was thinking of that, I do love my computer, but its also taken a lot of abuse over the years and is falling apart physically. The battery lasts, no joke, about 17 minutes when out of the charger (and I've even replaced the battery with a brand new one and after a few days of good battery life, it was back to that 17-30 minutes battery life when not plugged in... so I started to thing there was something wrong with the computer itself, not the battery...) The screen is cracked and so is the outer shell of the computer itself.
Right now, these are my options:
2.0GHz Quad-core Intel Core i7
8GB 1333MHz DDR3 SDRAM - 2x4GB
256GB Solid State Drive
SuperDrive 8x (DVD±R DL/DVD±RW/CD-RW)
MacBook Pro 15-inch Hi-Res Glossy Widescreen Display
None
Backlit Keyboard (English) & User's Guide
TOTAL: $2699
OR
2.2GHz Quad-core Intel Core i7
8GB 1333MHz DDR3 SDRAM - 2x4GB
256GB Solid State Drive
SuperDrive 8x (DVD±R DL/DVD±RW/CD-RW)
MacBook Pro 15-inch Hi-Res Glossy Widescreen Display
None
Backlit Keyboard (English) & User's Guide
TOTAL: $2999
My one question... is the upgrade from 2.0GHz to 2.2GHz really worth the extra $300? And would it even be worth an extra $250 to upgrade to the 2.3GHz processor??
Thanks again for all the replies! I've learned quite a bit in this discussion!