Upgrading from 7.2 does not automatically add rhn-applet to the package set. This means that people upgrading won't get any benefit from this spiffy tool. I think either gnome-core or rhn_register-gnome should require rhn-applet so it gets pulled in.
up2date-gnome now requires the applet in 7.3, but not in earlier
Actually, we backed this change out. What will happen now is that if you have 7.2 installer with gnome-core and up2date-gnome, then any new users who have panel configs created after the upgrade will get the applet added to the default panel. Will test that here shortly.
Behavior is confirmed with the latest code (1.0.6-10)