The ability to wrap our own code around the WebIDL bindings would be really handy for us. I just wanted to raise the idea of this being seperated out from gwt as part of the gwt nextgen work. For example, it would be great if we could submit a delegate API that's called by the Elemental WebIDL parser that then renders our code inline with respect to our specific use case.
It seems to me there are quite a few groups now working on java tech in the browser, for example, java2script, teavm, dragome, and doppio, libgdx, etc all with different goals and features. A common API could be useful to some of those projects.