When I first saw the title of the update, I thought it was going to be about being able to load your own music into the game to use as stage music. And I was thinking "Snap, a kind of nifty feature that I'll totally never use."
But then when I actually read it, I was pleasantly surprised. Now I can play on just about any stage and be sure that I'll have a decent song to fight to.
However, I must say, I'm not loving the white (well, more grey than anything, I think) menu look. I suppose it's a nice contrast to Melee's darker menu, but I prefer the darker to the light. This Brawl screen (which I first start worrying about when we saw the "Names" Game Mode update), seems too washed out to me. I liked the boldness of the black from Melee. This lighter theme bores me. But I'll save true judgment for when I see more screenshots of the thing.