Apple has made the following official statements regarding Cocoa/Carbon:
* First mention of transition of Mac OS 9 to Mac OS X: "Rewrite all your code in Cocoa."
* Shortly after complaints: "We will create a largely compatible API called Carbon that you can use."
* During the 10.0 to 10.4 evolution: Carbon gets a bunch of new features and in many
  cases evolves in lockstep with Cocoa, transforming it into a platform that stands on
  its own rather than just a compatibility/transition layer.
* WWDC 2006: "There will be a 64 bit Carbon and Cocoa, Carbon is first class citizen."
* WWDC 2007: "There will not be a 64 bit Carbon, move everything to Cocoa."

FML