There is now a set of functionally complete specifications for OpenID Connect. The diagram below shows the relationships between the current specs and contains links to each of them. These specifications are ready for early developer feedback and prototype implementation work. Please send feedback on them to the OpenID Artifact Binding Working Group Mailing List.
OpenID Connect uses the best practices of widely used OAuth/REST/JSON based APIs to define a standard and interoperable way to authenticate users. Developers should care because rather than having to learn an new and slightly different version of essentially the same API every time they want to integrate with a different identity provider, they can just do it in a standard way using a consistent interface. In the long run, OpenID Connect will make the web more interoperable, because it makes it easier for developers to integrate with multiple services.
FYI, the working group *is* planning to reorganize the specs to have the minimal set of OpenID Connect functionality be contained in a single document, although this will likely not be in place for a few weeks. Even before that is done, we wanted to make people aware of this set of specs now so early implementation work and technical feedback can occur. Remaining edits to the specs should consist of corrections, clarifications, and reorganization, rather than additions of significant new functionality. For now, developers should start with the (admittedly awkwardly named) OpenID Connect HTTP Redirect Binding spec.
Let the feedback and prototyping begin! [*1]
[*1] The easiest way to do is to join the AB list at http://lists.openid.net/mailman/listinfo/openid-specs-ab, submit the contribution agreement from http://openid.net/intellectual-property/ (which you can now do online!), and then send comments to the firstname.lastname@example.org .