I installed ie7 yesterday, its amazing how they can fuckup something as simple as tabbed browsing. You can't right-click on a link and open it up in a new tab. You also can't rearrage the toolbars so that the "File Edit View..." text is above the back/forward buttons & URL box.

It also does a number on the rendering of some sites, I take it they retried their css implementation in ie7 and that is causing some strange alignments and text issues. You should definitely check out how your sites look with ie7, they may be different.