Unless I'm mistaken, this is not video sharing like Youtube is video sharing. Hulu.com only allows you to share video that they (Hulu.com) puts on the site. In other words you can share the latest episode of Heros with the people who read your blog or share the video in an email.
I've been using the site since November and never noticed a way to upload personal video content.
I agree. From what I've read, the way to think of this is to view it as channel 100,000 on your satellite or cable TV box. At present, you can watch old episodes of commercial broadcasts on demand, with commercials. Think of it as TVLand on steroids. Over time, I suspect that original programming may appear, but it will all be sponsored content. You won't be able to skip over the commercials like you can with Tivo, but in exchange, you can get the content any time and, if the venture takes off, I suspect that perhaps every old TV show could end up on this "channel."
"At present, you can watch old episodes of commercial broadcasts..."
Not entirely true. I missed the last episode of "Heros" on NBC last summer, and Hulu had it. Also, we missed the first episode of "Canterbury's Law" just last Monday, and it, too, was on Hulu.