I am in a similar situation and my advice would be to wait.
1. If you are thinking of a machine for college next year, your current computing needs are probably already met.
2. Any discount that exists today (ie $100 off) will exist when you matriculate/start this fall. Plus, you will have access to the Back to School promo (ipod touch/printer).
3. My school store offers a better deal than $100 off so you might want to see if yours does as well.
4. Miscellaneous reasons: comes with Lion, refresh on macbook, potential of 2011-MBP 13" refurbs, 4 months more of use on the other end hypothetically
That all said, if I weren't abroad, I would have a tough time not buying this machine. I too am looking at the 13" and excited for the performance boost.
Good luck