As open-source integration stacks are becoming more and more mature the final push to convince the market about their usability seems to be to provide some sort of GUI for developing your solutions.
I recently blogged about FuseSource's release of the Camel IDE, and now it seems that Mule is joining the fray by recently releasing the beta of the Mule Studio Eclipse plugin.
Read more at: http://blogs.mulesoft.org/mule-studio-beta/
So now the major OS integraiton players (Camel, Mule, JBoss ESB, Spring Integration) all have visual support for developers. I guess only time will tell how these tools will be able to keep up with the quick feature changes in the frameworks.