According to Hardmac the Santa Rosa Macbooks feature more powerful USB ports. They provide 1,1 Ampere compared to the 0,5 Ampere of the previous models. Now, this is a cool thing, especially for people using a lot of high power USB devices (like external HDs).
One thing that I was wondering about though was, is the new Apple Aluminum keyboard more compatible? In the sense that I can connect my iPod to charge it via the port of the keyboard? If anyone knows I'd appreciate a comment on this because many Mac users were in fact very unhappy that the new keyboards were fully compatible with the new iMacs only.