I'm happy to see that I can now create social applications for Ning, Hi5, and Orkut.. (ok in their sandbox at least) and have done so already..
So how is OpenSocial BS based on this key point? OK its technically not too complicated but it got social sites moving quickly and thats a big plus in my opinion.
In my opninion none of this stuff is very hard technically (Facebook is easy sneezy as well really)..its the adoption of this new type of platform that is the key for me.. and Google seems to be knocking that out of the park..