Nothing I've been doing regarding social network portability is secret. I've been discussing it at Internet Identity Workshop, Foo Camp, OSCON, etc.
Yeah, I'll admit there hasn't been much in the way of blog posts about it. Those will be coming. And David and I will be at the data sharing summit.
But so far we've been discussing our plans with Dopplr (Matt), Twitter (Blaine, Goldman, Jack, Ev), Digg (Kevin), Pownce (Leah), Technorati (Tantek), Facebook (several, incl. Mark), Six Apart, Zooomr (Kris), Chris Messina, O'Reilly (Tim) and a bunch more at various events and coffee shops.
David and I will put together a more meaty post soon. Sorry about that... not trying to be secretive.