I was an happy owner of a Kindle Keyboard, on which I could easily manage my collections with Calibre and go on reading four hours a day for a month without recharging.
With paperwhite (first gen) I got roughly two weeks of charge even with lowest brightness because I can't turn the lights off, and for using Calibre I had to crack my Kindle and keep it offline or it would upgrade itself...
So whatever this update does, it's a NO-GO for me.