Sounds like another blow against home mechanics.

"Dangerous voltages. No User-servicable parts inside"

42 V is enough to kill in some circumstances, and you'll note that safety gets mentioned from time to time.

I guess this will also lead to the end of the 12V Halogen home lighting systems, or they will become very expensive when they are no longer using cheap auto bulbs but special made ones?

OTOH, there will be advantages. I used to have a 6V motorcycle (Very cheap, very nasty). I remember the joy of upgrading to a more modern 12V bike (which also had 3 times the cc's and 6 times the HP).

There will be consumer advantages, but god help you if your fly-by-wire car trips out and reboots at 120 mph. (it makes that joke about "If Microsoft made cars" horribly true!)