Why not make an extension to Nautilus applications:/// so it can handle rpm installations? (like OS X)
Example: if I drop an rpm file in the applications:///Internet, the rpm program will install as usual, but the icon for the program I installed, will show up under Internet in the GNOME-menu.
If some conflicts ac cure, YUM cold resolve the depencies, against the RHN (subscription based).
That cold be THE THING, that wold turn over new users.