Little bit of a bump for this thread with the addition of asking for widescreen support for loading screens (along with similar support for the login screen, server-select screen and character-select screen).
I'd prefer black space down either side of a loading graphic to a stretched image of the place I'm about to load into.
Especially with regards to the login screens; its a bit like having a beautiful house where you have to duck to get in the front door and the ceiling in the foyer/entry hall/atrium/whatever is 4'6" high.