We're starting to look closer at the potential for HTML 5 provide as an option for BigBlueButton to provide rich multi-media interface in a pure HTML/Javascript environment.
http://www.whatwg.org/specs/web-apps/current-work/multipage/
While there will always be limitations in a new platform, and we know its early days, but HTML 5 is showing some promise for supporting the voice and video streams that would be needed for web conferencing. This is definitely worth investigating further.