welp, I've finally gone and done it and upgraded vbulletin to the 4.x series.
Totally new styles, etc. We'll be using this to eat the front-page at some point, but for now just the forums.
Big thanks to Kraco for doing the icon theme work, and for the folks in the "new banners" fanart thread for the new banners you see up top. And to all the folks who did test driving on the dev forums, too!
Let us know about any style tweaks or other suggestions to make things better!