I was about to say the same thing.This FF mirrorless war is just the reason why I have hard time deciding which system to select if I was starting from nothing today.
Years ago when I decided to switch from analog to digital photography, I watched a very unstable market and I waited as I did not want to invest in a soon dead system. At that time, there was no risk of a company going out of business but there was definitely a risk of technology becoming obsolete very quickly or entire product lines being dropped (e.g. remember how Olympus dropped the 4/3 DSLR for the M4/3 MILC).
So my first digital camera was in fact a Nikon LS-50 film scanner. Then I bought a Panasonic FX100 compact camera (cute but terrible in low light), then an Olympus E-10 bridge. In 2009, I decided that technology looked stable enough and I saw a friend with the Olympus E-P1. I liked the concept and bought an E-PL1 kit (14-42 + 40-150), then a 9-18. In 2012, the E-M5 appeared and I knew I would stay with the M4/3 system.
I saw Samsung stop making camera, Nikon silently stopping its cute Nikon 1 series, Sigma struggling with the odd Foveon technology...
I don't know who will remain in the end. It is easier for a big company like Sony or Panasonic to drop their photography division, as they make many other things. Just like Olympus did. Maybe companies like Fuji or Nikon will fight more, as they are nearly dead without photography.
I think that if I started photography now, I would buy a cheap second hand camera and wait a couple of years until things calm down.