Thats one sweet design there, one of the best I have seen. The two things I don't like are the black and white scroll bars in IE, it doesn't match the site and the new post icon isn't very noticable unless you look hard, at least for me.
Perhaps also change the smiles and message icons from the deafult yellow to the green or blue you use, I think that would add the finishing touch
Other than that fantastic a very nice clean pro desgin, well done.