It's not. We should be spending time implementing Persona rather than trying to come up with new identity solutions. Mozilla browserid/Persona is good enough or better than any other solution presented thus far, and has the best chance for adoption.
I cannot agree with this enough. I implemented BrowserID on one of my sites once, and never looked back. Now every new project uses BrowserID as the only way to log in.
It is superior to all other ways I've seen in usability, which is ultimately what counts, and integration takes all of two minutes, much less than traditional password auth. Plus, you don't even need to secure any passwords.
I really, really hope it catches on, and Google/Yahoo!/other mail providers start supporting it.
From a usability perspective WS-Federation is far superior to BrowserId. Not least because BrowserId is hobbled by the browser, whereas WS-Fed works across any platform, any architecture (native desktop/phone/tablet, browser, cloud ...), any OS.
Note that this is my personal opinion. I think we should be trying to come up with new solutions - BrowserId/Persona some some identity problems, but nowhere near all.
Have a read through Kim Cameron's post [1] to get a feel for how naive, if noble, Mozilla's efforts are.
