The main issue with the 11" Air was the screen. An 11 inch widescreen with a 1366x768 resolution was just too limited.No body here mentions the 11” MBA. That model had both, the wedge shape and the maximum portability of the 12” MB.
I agree there’s space in the lineup for an ultraportable. I would give the 11” MBA the new models treatment. That would be a dream machine that you could hook up to a large monitor when home and still have an M2-powered workhorse.
I think if you're going for a sub-notebook, the 4:3 12 inch screen size seems to have the best balance of portability and usable space, the 12 inch PowerBook and MacBook confirmed this. The MacBook just let itself down in almost every other area.