Apple has made the complete new iPad event keynote video available through iTunes. You can find the video under Podcasts > Technology > Tech news > Apple Inc > Apple Keynotes. You can then download just the event video or subscribe to all future events when they become available.
The free download is 980.9 MB; so if you are on a slow connection it may take a while to download. You can always see the event as a stream on Apple's site if you can't wait for the download.