The current battery life of the airs , as well as the performance is currently good enough for people's needs.
If appl can reduce the thinness , while keeping the same battery life and performance , as well as add a retina screen , then it will be a winner.
People though will regret when/if Apple did move the airs into an arm platform. Currently arm is no where near at the performance levels needed for a good computer, and power consumption ain't exactly far better, certainly not enough to justify moving to arm considering Intel chips currently help provide 10+ hours already of battery life which is incredible.
Not only that but power consumption and integrated graphics keeps on improving vastly on Intel chips , so there is zero point In getting rid of Intel just for the sake of it.