The files created are all in open-source formats, including Theora, Vorbis and Ogg (support for WebM and other formats are planned in the product's roadmap). Once media is captured, files can be accessed via the DOM with HTML5 File APIs.
Mozilla also wants to enable live streaming video capabilities for the add-on.
Mozilla Labs employee Anant Narayanan wrote in a blog post today that the Labs team had "experimented with audio recording in the browser as part of the Jetpack prototype." This development, however, is still a pre-alpha prototype at the moment. As such, it only works with Firefox nightly builds on Mac devices.
Another Mozilla experiment we've liked a lot lately is Chromeless, a DIY tool for developers who want to create their own web browser UIs.