A new Firefox add-on, Rainbow, will make it easy for web designers to record audio and video right in their browser. The audio and video formats created would be in open formats (Theora for video and Vorbis for audio in an Ogg container)--accessible in DOM using HTML5 APIs.
The initial version will be built for Mac, but Windows and Linux versions are high on the agenda. Streaming video feeds is also a top priority for the project.