Jeff: I just saw both cars together at Stanford European. The Gallardo is more interesting visually and is well-styled. As we noted in 2002, the Murcielago is more classical and restrained. Both are pretty in different ways; it's like Hollandaise versus pepper sauce. It's classicism versus romanticism.
That said, Gallardo looks much better to me in person than in pictures. There's definitely a Countach reference in the shape of the sides.