Matthew Panzarino argues that it’s more about a unification of Apple’s two platforms:
Apple is going about unifying the iOS and OS X experience in a few ways, none of which have to do with ‘turning OS X into iOS’.
But many of which have to do with making OS X work more like iOS. So, that’s a pretty thinly veiled argument.
Apple has framed the marketing for both Lion and Mountain Lion as bringing ideas from iOS to the Mac. If anything, Lion had more big features unrelated to iOS than Mountain Lion does, e.g. AirDrop, Mission Control, Versions.
Unification is a great word, and I think it is pretty representative of how Apple is trying to forge ahead. However, the fact remains that today, the way that iOS and OS X are converging is by OS X taking lots of cues from iOS, and not so much the other way around. Call it iOS-ification, unification, or whatever else you want.
Do I hope the changing tides will eventually wash some things from OS X back into iOS, of course. But right now, that isn’t what’s happening.
Update, January 23, 2014: This MacWorld article sheds some light on how Apple’s executive team view this situation.