Google Instant is a new search enhancement that shows results as you type. You will get all the information from here. I had seen ytinstant.com which is developed by Feross Aboukhadijeh. Instant search for YouTube, you will get the result without hitting your Enter Key. I also wish to do something like that, and added the Instant search list below the search area. So while you typing on the search box you will get the suggestions from google and mean time the video will load according to the top match. You can quickly navigate to your suggestion list using up/down arrow key. If you are using backspace to erase the search keywords, it will shows you the latest top suggestion at the backside of your search box, like in the Google Instant.

At the home page you can see the Today’s top rated videos from YouTube.com. You can see my try here for YouTube Instant .