First he should find out what the school is using for video editing software. It's probably Final Cut Pro, but there's a chance they could be based on Adobe Premiere. If it is Final Cut Pro, then the 15" Macbook Pro is a great choice.
Leo suggests getting the 2.6 Ghz Core i7 15" Macbook Pro with the 256GB Solid State Drive, higher-res display, and perhaps a 27" external monitor. The retina display Macbook Pro probably wouldn't be enough of a difference from the regular Macbook Pro, especially if he's already spending more money on an external drive and monitor.