My advice? Download it swiftly, before it gets pulled.
*UPDATE* - My heaving mailbag reveals some of you don't know how to download a YouTube video.
The easiest way is to use a YouTube built-in downloading tool. First you need to download a piece of free software called Best Video Downloader. Then, go to the video's YouTube page by left-clicking on the title at the top of the video. You will see a 'Download' button just beneath the video. Click on your preferred file type (MP4 or FLV only) and that's it. It's a large file, so it will take a few minutes to download.