We'll see who's right come 2015 I guess.
They would have been separated before due to resource requirements, and also to enable apple to gradually phase touch into OS X and OS X features into mobile devices as capability of said devices improves.
By 2015 sure Touch vs Keyboard might have become very fuzzy but another divide that ensures strong difference between iOS and OS X will become front and centre*. Their not going to produce a middle ground. Middle grounds lead the sort un-focused mess Apple was in the "Beleaguered" Days.
*The divide is really sitting vs standing which isn't going to change even if both have touch, keyboard, voice it'll always override how you implement those things.