gnome-vfs2-2.7.92-3 does not include a mapping for application/ogg, I
suggest using xmms and/or ogg123. Background is that I receive voice
messages as .ogg attachments and Evolution can only save them to disk.
This certainly works for me on FC5. There are plenty of applications that
gnome-vfs2 maps to ogg, and Evolution gives me a bunch of options to deal with
ogg attachments. I'm not sure exactly when it was fixed, since this bug report
is pretty old, but I'm going to close it.