...and so i will say this again: let's wait for the benchmarks. PLUS...let's see how user's real-world experiences go.
facts are so much more useful than guesses and speculation (altho, to be fair, guessing & speculating are fun things to do).
there are already benchmarks of the mb2015 components and they are like a low end machine from 3 years ago.
there will be a 14" macbook with more ports soon anyway. apple has a netbook category now. it won't replace the mba or mbp anytime soon. netbooks do what netbooks do.