Here we go ...

TechCrunch both right and wrong .... OpenSocial can't claim victory until the users turn up.

But wrong ... because they still think it's all about squirting one chunk of HTML / Flash / Javascript into another.

And if their OpenSocial apps start to gain more traction because they have more functionality, they may just start to put those Facebook projects on the back burner. (With OpenSocial, for instance, full applications can run on members’ profile pages, whereas on Facebook there are substantial restrictions on what developers can do on those profile pages).

OpenSocial apps aren't going to have "more functionality" in any meaningful way. Because social applications are not like desktop or browser applications. The only functionality which is important to social widgets is "social functionality" and that is dependent on the richness of access to, and the sophistication of manipulating, the social graph itself.

OpenSocial is extremely unlikely to be able to offer as rich a functionality in this sense as Facebook (or, indeed, any particular YASN) can, because it's got to be a least-common denominator between a number of very different philosophies of what a YASN is and is for.

Having said that, this is a very cute thought :

Joining OpenSocial could actually be a brilliant move for Facebook, especially if it can become the advertising network of choice for social apps. If Facebook can make it easy for Facebook developers to port their apps elsewhere and power those apps with Facebook ads, why wouldn’t it do so? Checkmate, indeed.