I want to have an arbitrary number of separate video displays that are somehow projected into space around me, with no physical, tangible component. I want to create new ones at will and dismiss them just as easily, independently re-size and re-locate them, and to move content back and forth between them and to run anything I want in full-screen mode without it interfering with my interactions with other applications or content.
However, I also know myself. I know that I would make lots of displays. I'd have some that I'd never dismiss, and I'd grow dependent on them. I'd open almost everything in a separate one, so that I wouldn't have it competing for real-estate with anything else. I'd avoid closing any until I was sure I wouldn't want them anymore. And why not? I can have as many as I want. So the space around me would gradually grow more and more cluttered. There'd be too many to keep track of, and just trying to deal with them all would actually start to become stressful. But I wouldn't be able to want to go back to not having them. I'm not even sure if I could go back.
On the other hand, I know this without having ever tried them. And since I've never had access to this technology, I'm not tied to it. I can escape from the added stress without ever having to give up anything that I already have.
So why am I not grateful?