I went with the Macbook + 2GB RAM. I also got an NC4010 off of
http://www.retrobox.com for $290, which was pretty sweet. Value-wise, the NC4010 slays the Macbook in every way, but I am still happy with my Macbook decision. It is an excellent machine.
Here are some other factors about the Macbook vs. the Macbook Pro:
Keyboard - the Macbook's keyboard is very different from the Macbook Pro. Personally, I like it better. However, some people on the 'net can't stand it. I would definitely check this out before you buy, because it can make a huge difference.
Weight - the weight of the Macbook is terrible compared to the Macbook Pro, and especially to other notebooks in its class. The Macbook Pro has a 2" larger screen, but only weighs .4lb more. My HP NC4010 has a 12" screen, 1" less than the Macbook, but weighs only 2.5lbs - 1.7lbs less than the Macbook! The difference is very, very noticeable, and not in a good way.
Speed - The graphics is the only real difference in speed. However, there are few reasons you would need the type of graphics card in the Macbook Pro. The main ones would be a) gaming b) 3D design or c) heavy Aperture (photo editing) work, all of which are unlikely for a prospective law student. Things like Google Earth and Google Sketchup will run fine on the Macbook's integrated graphics. They are DirectX 9 compatible, so Windows Vista will work as well.