I think I'm a freak, because I want a huge MacBook.
I buy desktops with lots of power and that can drive major pixels, both for fun and work. admittedly, my work requirements are modest, mostly Office with a bit of the Creative Suite. But Office along with lots of Web stuffs pays my bills. In my free time, I do video editing and things that require a bit more juice. Still, I like a desktop, because I drive lots of displays.
For a laptop, pixels are more important than horsepower. Frankly, for the way most of us work, I'd argue that screen real estate makes us more productive than CPU oomph. So, for my work laptop I need real estate. I want to have a PPT next to a web page, or outlook next to a word doc. But still, I want some mobility.
So, I'm probably about the only person in the world who would like to see a 15" MacBook. Yeah, 15" McBook. In my dream, it only needs a bit more horsepower than my current 12" has, and mainly in the GPU department. With a 15" size, having roughly the same sized circuit board, I bet we could get 15 hours of battery life? We could also push a 4k or similar display. Anyhow, I'd like to see that. Stretch it two inches to get 50% more battery life and pixels. Then, for 95% of what I do that's work-related, I'd be more productive than with a 15" MacBook Pro.
But again, I'm a freak.