The ebuild installs the .desktop file into /usr/share/gnome/apps/Application/. This should be changed to /usr/share/applications/. And the .desktop file points to /usr/bin/emacs-21 which does not exist (only /usr/bin/emacs.emacs-21 does). Reproducible: Always Steps to Reproduce:
*** Bug 88361 has been marked as a duplicate of this bug. ***
Thanks for the report. Fixed in CVS.