What I do like about this site is the ability to post in the forums on the most popular topics where everyone can join in the convo, not just your friends, like FB (I dont think FB has this, not sure, not a huge fbooker). I used to like the PM set up, *sigh* . I love the signature thing. The smilies rock...I wish my blkberry had those. lol. Umm, I like knowing when new members join. Even if I don't know them, I'd like to say howdy.
Now, I would like to see, taking it from FB, the whole 'search for friends" thing. Its much easier on FB to search for people. The friends in common thing is cool.
This is all I can think of right now.
P.S. Maybe they can make the site pretty. Choosing the right fonts is everything. And why can't I see my picture and some other peoples pictures? I need to know what I look like! lol