Facebook apps on any website! RIP OpenSocial?

Facebook PlatformQuick update.. I just learned via Tech Crunch that facebook has opened up a brand new client library, that makes it possible to embed ajax-nifty facebook applications on any website! Plus, there’s no local server-side code needed, so users can simply paste embed code into their site – much like embedding a simple YouTube Video. No other setup required.
So, will this hamper the adoption of Google’s OpenSocial? Why would I want to use an Open Social app with (currently) limited reach, when I can simply embed on my myspace profile an app from facebook that all of my friends already use?

Finally, as Adam pointed out last week, social networking on mobile devices is just heating up. In lieu of full-on facebook on my phone, what if I could custom create one-off widgets for my mobile phone (eyeing the iPhone here) out of Facebook applications? (Read on Tech Crunch)