Here's what I would love to see. And I'm 90% sure there are companies already thinking & working on this.
I'd love to see a service that offers various "channels" of video content. These channels would be genres, like food, home, comedy, action, etc. The content would be a mix of amateur videos (like home videos), semi-pro videos (like amateurs who've worked hard to create near-professional quality videos), and professional videos (created in formal studios with a full staff).
I could subscribe to particular shows within a genre, or just let a channel play random shows for me. Shows could also be recommended to me in a Pandora-like manner that uses my previous viewing behavior + my active ratings to determine my tastes. Most popular shows could also be shown somewhere, in case I wanted to browse what's hot right now.
As an example, my wife loves cooking shows. She's found a few amateur/indie chefs on YouTube that seem just as good as "professional" chefs with their own produced TV shows. It would be great to view both types of videos in one place.
I love sci-fi and action movies. And you know what? Twitch.tv is pretty damn cool too. As are some cinematic game trailers. I'd love to see all of that in this service too.
This service would come with integrated hardware, much like Roku. In a way, this idea is like Roku, but with YouTube videos bundled together. Plus, a "video genome," a Pandora for videos. Oh, and a much better UI.
To the people who are already thinking & working on this, please hurry. I can't wait to give you my money and subscribe to your service.