My colleagues from the RAP Team have created proof-of-concept implementation of a web-enabled Draw2D port. This could eventually allow you to port existing graphical applications based on the GEF/Draw2D frameworks to the web.
Click here to watch the video.
So will this be available as part of Eclipse RAP soon?
No, this work was intended as a feasibility study. At this point we are looking for parties that are interested in using and productizing this technology.