I need services spanning websites; protocols that can break the bonds of individual domains. I need a universal wishlist that isn't dependent on Amazon at all, a friends list that doesn't care if it's used on Facebook or not. And I need those services, despite being website-independent, to operate with those websites seamlessly, so that I can (for instance) shop around for good book prices on my wishlist.
Think in terms of email. Before the standard emerged, only users on the same network could email each other. That's like needing several different mobile phones on different networks to allow you to call your friends on the different networks they've chosen. That's exactly the situation we currently have with social networking right now. It's a ridiculous situation that's crying out for a unification of standards. We need people on Facebook to be able to connect directly to their friends on Google+ and MySpace, without anyone needing to switch websites, maintain multiple accounts or sign up to yet another website that aggregates the others. We need Twitter to enable followers from Buzz and Tumblr. We need Live Messenger, Google Talk and Facebook chat to be seamlessly cross-compatible. We do want competing services, but we need them to compete purely on user experience, not critical mass or proprietary features. This will take a long time, especially when it's easier to keep your users by locking them up than by being the best.
Mokalus of Borg
PS - The first of any new type of service is unlikely to be open.
PPS - But once it becomes common, it needs a standard.