If you are a student you can get a small discount on the Apple Store web site by clicking the Education link. The 13 inch Macbook Pro is $1099 on that site -- well worth the extra $150 over the Macbook. The extra RAM is critical for Photoshop and FCP, and the metal body is better (I've had both.) For your uses, a larger hard drive is worth the cost, too, as it will be faster. Also, check the refurb units on the Apple store web site, they might be slightly less expensive than the education prices.
You might read some of the pages at
http://macperformanceguide.com/index_topics.html -- lots of great information there.
The extra screen real estate of the 15 inch is good, but it's still not really large. If you want a larger screen for editing, an external monitor is less expensive.
Finally, you might not want to buy this week. It is widely expected that they will release new models next week. Then the current models may be available as refurbs for a better price.