Seems it’s official: MySpace is joining Google OpenSocial . This is a huge boost for OpenSocial API.

I’m looking forward to see all the great 3rd party applications from Facebook also on MySpace. Obviously there is a huge incentive for these application providers to embrace the OpenSocial API: Millions of MySpace users are joining in!

Maybe one day, Google will launch an initiative to support one Rule Markup Language. Being RuleML or anything. As long as there are enough participants, a standard will evolve.
This would open the door to the Web 3.0: putting the semantics on top of hyper text.