@ Portable companion battery that plugs into MacBookPro power input
I used to have one of those for my PB 170 - called a 'powerplate' or some such, at least it let me work for an entire Manchester - London train trip, quite something in those days.
I read that the new Macbook will have 'intelligent' batteries controlled by dedicated chips - something that caused endless hassles in the days of the Blackbird PB 540.
Whichever way they try to justify it, a non-replaceable battery is a stupid decision that both Apple and its customers will come to regret.