I'm in charge of development of Xored's Q7 Eclipse GUI Testing tool:
http://www.xored.com/products/q7/ . Recently one of our engineers recorded a quick demo for a customer using JWT as an exemplary app, and showing how Q7 deal with GEF-based applications. The video is here:
http://www.youtube.com/watch?v=jtzIF6VX3Fo and I'm decided to share it within this project list -- for the reason JWT team may be interested in UI testing for JWT.
The product is free for open-source projects, and there are a few eclipse projects using it already, such as Eclipse DLTK, Eclipse Tigerstripe, and LDT. Please let me know if you'd be interested in any help related to JWT UI Testing.