This is an interesting podcast with discussion among a group of tech journos. They put forward the view that, under Cook, Apple looks like is merely keeping MacBook on life support until iOS is in a position to replace the MacBook for most users (hence the lackluster recent offerings). And it seems that Apple seem to care less and less that in doing so they alienate their traditional supporters in the design industry as this segment is only a small portion of current total Apple revenue (hence the no upgrade in Mac Pro for three years).
Here's the link - the Apple discussion starts at around 27 mins into the podcast (if you want to skip straight to it).
https://twit.tv/shows/this-week-in-tech/episodes/587

