In nautilus, floppies are treated just like CD-ROMS - a icon is only displayed on the desktop if the floppy is mounted. Unfortunately, old-style floppy drives (as opposed to USB floppies) don't support autodetection, so mounting has to been done manually. What gmc did was to always display a floppy icon on the desktop, and you could right click and select mount, or select format (which would run floppy-buddy) Since NautilusVolumeMonitor only deals with volumes that are there, this would probably have to be special cased, perhaps as special desktop files like the trash can. FloppyBuddy has code in it to autodetect floppy drives that could be used. This is a pretty serious problem, since the only way to mount a floppy is by starting a shell and typing 'mount /mnt/floppy', but its also a lot of work to fix.
We (Red Hat) should really try to fix this before next release.
It turns out that you can actually right-click on desktop and choose Disks->Floppy. Kind of hard to find, but it does exist.