No, there's no live feed, although MacRumors will provide live text (and picture?) updates via
http://MacRumorsLive.com during the keynote.
After several hours a video will be posted on Apple.com, although if you wish to watch the keynote without and knowledge of released products or announcements, MacRumors also provides a spoiler free page which will contain a link directly to the video, allowing you to bypass Apple's homepage and the MacRumors homepage, which will both contain information about the outcome of the keynote.
I'm sure more information regarding MacRumors' coverage of the keynote will be forthcoming as the event approaches.