If a picture is worth a thousand words, this graph from Hitwise is worth a thousand page views. The graph shows the market share of visits to all OpenSocial members combined versus Facebook. Clearly, Google's OpenSocial is a force to be reckoned with.
The question, however, is just what we're supposed to do with it. Thus far, I can't really understand what I'm supposed to do with Facebook. Google's OpenSocial has brought me no closer to grokking the nirvana that has apparently been unleashed. Jack Schofield in The Guardian gives two good reasons why:
First, as far as I can see, it's just a widget format, i.e. Google Gadgets. I'm sure there is value to having a common Google-sponsored widget format for mini-applications, because it reduces the amount of work needed to put Vampires or whatever on different social-networking sites. But really, who cares?
Second, I can't see what's open about it. Sure anybody can write apps for it, but anybody can write apps for Facebook, or, indeed, Windows. There's more to come, but at the moment, it looks just as proprietary as the Facebook system it more or less copies. The main difference being that Google appears to own and control the OpenSocial container/API in which the widgets run. But should it feel the need, Facebook can make its system just as "open" as Google's, simply by allowing other sites to host Facebook apps.
By Google's reasoning, Microsoft Windows is also "open." No one prevents me from writing applications to run on Windows--in fact, Microsoft bends over backward to help developers do just that. Why is it "open" when Google lets people lock themselves into its platform but it's closed when Facebook or Microsoft invites people to write to their platforms?
Hint: It's not. Google is just better at marketing its "openness."
Regardless, by embracing disparate sites like Ning, MySpace, and others, Google has stolen the march on Facebook with numbers (see above) that suggest it will be very hard to beat Google on its own Web turf.
All of which should make us worry far more about Google than we ever did about Microsoft. Microsoft owned (and owns) the desktop. That's scary, but it's not nearly as bad as putting a lock on the Web, that network of networks of little Microsoft desktop fiefdoms.
Is Google evil? No, I don't think so. But it will become increasingly difficult for Google to grow without stepping on toes...and laws, just as Microsoft did before it.