I think this was brought up a couple of times on IRC, but to get some additional interest by all the devs: Adonthell has a pretty sweet dialogue editor by the looks of it. I haven't tested it myself but it really seems worth a look:
http://adonthell.berlios.de/doc/index.php/Tools:Dlgedit:ContentsMight be a great way to get inspired and learn from their insight :-)
