The way you completely lose your page tabs when switching to Special:MovePage has been a bother to me for awhile... it's bad interface design to have a set of tabs linking to other pages with the same set of tabs, but to have a single one of them strangely point to a page where those tabs completely disappear.
1.18 has a new feature now. From a special page you can call $skin->setRelatedTitle and $skin->setRelatedTitle. Calling setRelatedTitle will mark a title as relevant to the current page, doing so will cause some parts of the ui (namely the page tabs) to display things relevant to that page. Calling setRelatedUser likewise will cause some parts of the ui (namely the toolbox) to display things that they would display if you were on the user's userpage. These methods are currently used by Special:MovePage (title), Special:Undelete (title), Special:Contributions (user), and Special:BlockIp (user). If you have another special page you feel is relevant enough to use these methods feel free to tweak it's code.