I think we had a talk on this before. But my experience with transports is bad. They are less reliable, offer less features and if one of the protocols change you can only hope that whoever runs the server fixes it. Also most unexperienced uses would rather click on that .install file for pidgin instead of setting up transports...

Hmm yeah but they don't make as much use of it as i would like to see. Also i have not seen i 3rd party app using it yet.