The Ubuntu website and basically all the official Ubuntu related websites have been upgraded to use the new Ubuntu branding, except for Ubuntuforums.
But that's about to change. Mike Basinger create a blueprint @ Launchpad regarding this matter which has already been accepted, so it looks like we'll be getting a new Ubuntuforums design soon (I'm not sure when).
Mike also posted a link with a test theme for Ubuntuforums. To check it out for yourself, head over to www.mikesplanet.net/forums. What do you think about the new proposed design (note: the link is marked as "test theme" so it may not be the actual new theme or it may change)?
Update October 31: Some changes have been made to the design so I've updated the screenshot.
Update October 31: Some changes have been made to the design so I've updated the screenshot.