The goal of Opera Unite is to allow everyone, even non-technical users, to serve and share content and services with one another, without middle men like Facebook, YouTube, and so on. These features can be unlocked by applications; for instance, a demo application from Opera, called Jukebox, allows you and each of your friends to put up to 10 songs in a queue. This list of songs will then be played randomly to all your friends on Opera Unite (who joined in, of course).
While the Jukebox may not seem like reinventing the web, Opera states that this is just the tip of the iceberg. "The Opera Unite Jukebox is just one simple example. Opera Unite services can be just about anything. It's up to developers, companies, entrepreneurs, end users, and anyone with a vision of what the interpersonal Web really means, to take that vision and build the next generation of applications that bring people together online in brand new ways," writes Lawrence Eng, product analyst at Opera.
The main point here that Opera seems to be making is to take away the reliance on 3rd parties, allowing you to host your content yourself. They see a future in Opera Unite for collaborative word processors and spreadsheet applications; much like Google Docs and such but without having your content hosted somewhere else. However, isn't that one of the selling points of server-side applications? As in, it doesn't matter where you are, you can always work on your documents?
One of my immediate concerns was that of security: how secure is Opera Unite? Can everyone just connect to my Unite "web server" without me knowing about it? Doesn't this open a whole new attack vector for web browsers? Opera states that the web server is not enabled by default, but what if you leave it running by accident? I'm a little weary of this.
In any case, I guess this is one of those typical technologies where the benefits aren't immediately obvious, and where it will all depend on what developers will be able to do with it. Unite in and of itself isn't exciting - what could be exciting is what developers can do with it. I'm sceptical, but before passing any judgement, let's wait and see what developers can come up with.