The title is kind of obvious, and the speculation is interesting.
Personally, and given that I’m not sure I want to deal with an entirely new (first revision) MacBook Pro and have much more use for a desktop these days, I’m hoping the Mac mini finally gets a proper upgrade.
As much as I like retina displays, the iMac G5 made it abundantly obvious that all-in-ones are not the right kind of desktop for me, and I would rather not buy an iMac unless I absolutely had to.