You'll notice that Web 2.0 apps like to open to private beta. (I think Google started this with Gmail but don't quote me). Lately, the requests for an invite to GrandCentral (voice management portal acquired by Google last year) have piled in. It's the new viral marketing.
And now come the portals. Aastra's XML developers portal. Simple Signal. Open Social. iPhone SDK. Broadsoft. Lots of companies have decided it is much cheaper to let others develop apps for their platform. It's a form of social networking. You have a community site for users and developers that you get feedback through. It's a corporate marketing decision. As the Web 2.0 dev folks know, having an open API means more uses for your platform.
Now comes the part where we try to figure out the revenue model -- and the IP ownership. In today's patent troll world, who owns the Intellectual Property of what you use, develop, store?? (It's the one big question that was left unanswered at FOWA).
We'll see how it shakes out.