Most of the graphical packages (like firefox, or gaim) depend on the virtual package virtual/x11, the only version of which depends on xorg-x11-6.8. We need a new (masked) virtual package depending on xorg 7.0, so that dependencies work correctly
No, there is no virtual with xorg 7. If you feel that it really is a bug, file a bug about the package that is trying to pull in the old xorg via virtual.
And, don't forget to search first, to be sure that its not already been reported :)