Here's real-world breakage due to the old vendor prefix in .desktop
$ rpmls empathy|grep desktop$
GNOME Shell wants "empathy.desktop" instead for its default Dash favourites:
I've not opened a bugzilla report about this, because there are over 200
open tickets for empathy, and I can't tell whether the empathy packagers
would like the suggestion to rename the .desktop file instead of gnome-shell
having to be patched.
It's time to get rid of the old vendor prefix, even if that causes minor
breakage for app links on desktops.
Fedora release 18 (Spherical Cow) - Linux 3.7.2-204.fc18.x86_64
loadavg: 0.46 0.24 0.17