More obvious distinction between accounts, groups, and buddies.
Just a very small UI complaint: It would be helpful if there was a distinction in margin between accounts and groups - the difference in colour between the two is quite small by default, and is not there if a group is selected - a margin would give a more reliable cue. At the same time, a slightly larger margin for individual contacts would be good, although this isn't as important as other cues are more obvious, like background, icons, etc.