Size is fine, what I despise is that most laptops I've tried to keep alive over the past 10+ years, simply don't work without, at least, a minimally functioning battery installed. I should be able to take the battery out and use the laptop plugged in without fear of the dying battery exploding.

If laptop batteries can't grow, I assume there'll be a little extra pressure towards saving power, as people try to progress somewhere.

ARM laptops are said to be much more efficient than Intel. Just two cents' worth of hearsay.