There will be the one Macbook not others. Just like there was the one macbook before. They made the keyboard exactly the size of the body and went on and on about it and the proportions being in perfect harmony. etc.
The second tier will be the air replacement whether they call it that or not. It won't have core m. 3rd tier pros.
That's seems logic. But a 12" design doesn't mean there could be a 14" design with 13" form factor, and that would take the Air spot. Again, nobody knows, but they won't stop selling Airs, they will just probably not redesign 3 lines but only 2 (Macbooks and Pros).
I might be.. Who know's.
Maybe not much shows on benchmarks but I can tell the difference easily going from MBP 13 to 15. Could be partially graphics related.
I'd say there is enough of a difference on chips alone but there are more than enough other reasons to have 3 tiers.
Come on guy, you must be kidding or you don't read my answers. My first answer to you:
The only real performance gap is between 15" MBP and the 13" Macbooks
Not only because the graphic, but mostly because the 13" being dual core and the 15" being quad core. Even a 15" from 2012 is way faster than the 13" from last year.