They all knew that there was no competing with facebook under the current circumstances. So now all the social networking sites have teamed up together (imagine those meetings!) and have created OpenSocial, a set of common APIs for developing social applications. According to Google:

The OpenSocial standards are designed to evolve through contribution from the open source community and as new features are developed by various partners. Global members of the OpenSocial community include Engage.com, Friendster, hi5, Hyves, imeem, LinkedIn, Ning, Oracle, orkut, Plaxo, Salesforce.com, Six Apart, Tianji, Viadeo, and XING.

This was unofficially reported by TechCrunch on Oct 30, but it was not until today that Google made its official press announcement.

OpenSocial is really being marketed to developers - it does not require a special markup language and it is much more flexible than the facebook applications which only have functionality on the canvas page - the widget on the profile is generally useless and non functional. This is very exciting for developers, but I don’t think that this poses any kind of threat to the facebook platform and community. There are too many users already, and there will not be a mass migration anytime soon. While developers now have great opportunity, and marketers have another place to put their branded apps, facebook will grow and grow because they did it first. And the average user does not really care about markup language and flexibility (!). Furthermore, I have no doubt that eventually facebook will join OpenSocial to benefit its users and developers.

Supposedly on Nov 1 the OpenSocial API info for developers can be found here, but still not live when this was written.