Then ignore those forums in your options panel.
Check for features before whining kthx bai :p
Thank you for treating some of us who spent a lot of time here, be that as general users or people actually trying to help the community, like idiots and trolls.
Most of us came here, to wowace, as newcomers to wow addons, the writing of them that is. And we learned, we had a set format we got used to - the forums. We knew the options, the layout etc. Now we're in vBulletin, while it's not my preference, we deal with it. But slapping that into our faces, while we're trying to be constructive to get the forums a little more usable for us - which in general was appreciated before.
Navigating and setting up stuff on these forums takes me a whole lot longer as it did before, I can't check posts how I used. I can't get to "View last UNREAD post" only "View last post", which I am sure is extremely hard for visually impaired folks. We get to see posts that aren't even related to the game for which we write addons, so yes - we have a right to bring that to the administrators attention. I am certain it will get sorted one way or another. This method is how developping things works, especially things that are - while being worked on - visible and usable by public.
If I was in a position to have vBulletin, I would try my best to write a theme for it myself, I've done it in the past (IPB, PhpBB, SMF) just not for vBulletin. But I am not paying for a license to write skins, which is why I quit in the first place :P