og
When i move the mouse over an internal link, normally it's DW path is shown (e.g. "home:user:og:start"). This is even if "useheading" is set. I wonder of the value of this information for the user. Showing the h1 of the targetpage also in tooltip makes no sense either. In my Wiki i'd like to hide internals as much as possible, so i would prefer showing the "resolved" namespace-path, like in "you-are-here"-bar.
Another approach is to show a customizable text, which is fetched from the targetpage itself or it's metadata. So kicking off some AJAX to fetch the rendered code of the target page, open some small JavaScript overflow window and show the content.
This functionality could be even helpfull on searchresult pages, because one could peek into pages before opening it.