Tribunal is a GTK+ app and doesn't need to depend on Twisted.
OTOH twisted provides some useful glue for guis - at least, I quite like writing guis in it. Still, setting to confirmed wishlist for now.
I doubt there is actually a technical dependency at the moment. I don't strongly care either way: gio is probably enough what tribunal needs to do to stay responsive.
Bug watches keep track of this bug in other bug trackers.
OTOH twisted provides some useful glue for guis - at least, I quite like writing guis in it. Still, setting to confirmed wishlist for now.