Per discussion at Audio WG f2f 2013-03-26
The section on OfflineAudioContext states that "rendering/mixing-down [is] (potentially) faster than real-time". Need to specify that the rendering should be "as fast as possible", with no relation to real time.
Web Audio API issues have been migrated to Github.
Closing. See https://github.com/WebAudio/web-audio-api/issues for up to date list of issues for the Web Audio API.