Overall I think Youtube IS a jewel of the Internet. The amount of astoundingly interesting, informative, entertaining, educational, insightful, important or just plain COOL content that has appeared over the time it has been up is phenomenal, and it is like a Library of Alexandria of our time.
My big fear is that someday, Youtube will no longer be profitable. And then, like so many other beloved services, it will send out an e-mail saying it's been a great X years, blah blah blah, we'll be shutting down in a few months, bye.