just an idea: could we use a modified libhildonmime to do this instead
of the dbus switchboard?

it strikes me that this should automatically do much of what must be manually
configured for switchboard by looking at the standard package mime
definitions.

checking the source, libhildonmime is based on standard gnome-vfs-mime
but will only launch apps for which there is a dbus service entry. we
could modify this to also launch command line apps. similarly for uri
handling.

to open files and uris from command line, a simple "gnome-open" like app
that uses hildon_mime_open_file and hildon_uri_open would be fairly
straight forward.

any takers?