From what Steve said and from putzing around on the YouOS site, it would appear that they’ve tried to make the user experience as close to an OS experience as possible. There are plenty of UI plugins so far that include such new standards as Flickr, Gmail, weather, etc… and even wallpapers if you want them.

If you’re into developing in Javascript, the ability is there to develop plugins for YouOS and possibly charge the users that use it. I would expect that most of the simpler ones would be free of charge, but that the more extravagant one could be priced somehow.

The team behind YouOS reads like a who’s who of tech schools. MIT, Stanford and CalTech. There’s plenty of info to be had on from their landing pages, with FAQ’s and such.

5. Why? We set out to answer the following questions:

• Wouldn’t it be sweet if open source development was more like a multiplayer game, complete with rankings and all?
• What are the implications of being able to share windows through a buddy list when we’re working?
• Is it even possible to build an OS that is built on sharing from the ground up? Like Kindergarten?
• What if the OS itself was the community? Discuss.

We’re still searching, and YouOS is the search engine. Well, it’s not a search engine, but you get the analogy, right?

Looks like it could turn into quite the tool. I’m signing up for a full account and will try and update with new information as I can.