After too much attention and hype by media and bloggers, Google Instant is probably the most talk about product by Google. I am sure like Google Instant, many search engines will try to develop their product in future. But hey, if you want it for YouTube, then it is available right now.
YouTube Instant has been developed by a computer science student at Stanford University named Feross. This brilliant guy made a YouTube instant search engine that instantly displays and play the result while you type.
If you move to YouTube and search for the same keyword, you’ll find that YouTube Instant plays the top result came on the real YouTube search.