It looks like it has better antennas on it.
http://www.linksys.com/servlet/Satel...=0458039789B09
It also has MIMO technology, but you probably have to have a special Linksys card to take advantage of it because MIMO isn't part of the 802.11g spec.
I'm going to disagree with Zoomy because it's hard to find and costs twice as much as a regular WRT54G. At $80+ you'd be better off getting a 802.11N router which every device that is N compatible can use MIMO.