I put this on comments but I'm going to paste the same here:
Very nice changes, I have some recommendations of some errors, there are very simple:
1. In the bottom you have a white space with 18px of height, actually that white space is for Google iframe, you can set height:0 and if you have troubles perhaps a position:absolute can be help, I try to fix it in developers panel but I cant check because I cant refresh the website without lose the changes.
2. The "#mbnf .mbnf_community" is small, you can set height:35px and fix it.
3. "#mbnf .mbnf_top_back" is small, you have to change the height or you can set to "#mbnf .mbnf_quote, #mbnf .mbnf_quote a" a font-size of 12px and fix it.
Another possible change, thats a recommendation, Facebook Beta has the same but I think is not user-friendly: the header pins to top when you scroll up, I think thats better pin it all the time when you scroll down, not only in the scroll up.
Great work, love WPCentral and sorry for my bad english.