Not only that but such a high pixel density in a Mini might actually lead to a poorer user experience. The GUI could literally draw lines or dots on screen that most people won't be able to see. On the flip side iOS is somewhat resolution independent so you won't get the same results anyways as you get with iPad.
The other problem is that retina does impact performance of the computer it is installed in. Since I'm not expecting a process shrink again for 2013 it is hard to imagine excellent performance in an iPad Mini. The only thing we could hope for is Sharps IGZO screens which might allow for a clock speed bump in the processors. As for Mac Book AIR there you have an Intel GPU running at a low clock rate, that would need to be upgraded to support Retina.
Does a Retina display have an effect on performance? Sure, but it's worth remembering what happened with iPad 3 ("New iPad"). While most reviews felt that it was an improvement over the iPad 2, it didn't really have the necessary internals to smoothly drive the display (At least without putting the GPU under pressure - Potential heating concerns on this model). Even if the A7 (or possibly A7X) isn't a die shrink and instead a new architecture, they've had 2 previous generations of iPad with the same kind of display, so we probably will see better performance in that regard.
The "roadmap" (if we can call it that - this is Apple, after all) makes sense, no one's surprised by that. However, I do wish that the timing doesn't end up being as spread out as he believes it will be. The Retina MacBook Pro hasn't seen an update since June of last year, I highly doubt that they would wait an entire year to update the flagship of their notebook lineup.*
As far as AirPort is concerned, it seems like they are waiting on 802.11ac before releasing new models, do we know if Haswell (or Broadcom, I guess) includes support for this? I would also like them to potentially drop "b" compatability, the last 802.11b device I have that gets any use is a Wii and with the recent introduction of the Wii U, I'm not holding my breath waiting for any further system updates.
On a different note, seeing this kind of forecast makes me miss the time period when Snow Leopard was the focus (2009-2011), Apple understood that they had Pro customers that depended on Mac OS X and couldn't abandon them just to chase gains (however profitable) in terms of consumer marketshare. They were proud of the Mac and it showed. Now, not so much.**
* Owners of the 13" MacBook Pro or MacBook Air may disagree, but the 15" has, and will likely continue to be the technology flagship for the laptop line, a move to update the 13" model was only really done to bring the display to that form factor.
** See also the removal of Apple's "Science" website in recent weeks.