i dont think facebook is going to die now with ios 6 facebook integration
look at how many peope own an iphone
this is not just an app this is INTEGRATIONWhat does the iPhone have to do with anything? Any social network can make an iPhone app, not just Facebook.
http://www.apple.com/ios/ios6/#facebook
What do you think Facebook has to do to survive in a world dominated by mobiles and tablets? Can it survive without a Mobile OS, Browser or it's own phone?