http://www.sitepoint.com/html5-full-screen-api/they are working on a fullscreen api.
i like webgl.
i think the graphics part is totally ok already for non-highend games but javascript still is a bit slow for running a real physics engine.
i think a proper audio api (to enable stuff like pitch shifting) still is in the works too.
edit:
http://steffe.se/?p=677i find this project interesting. the automatic conversions of c++ physics engines like bullet all seem to be quite slow so far.