John McWilliams wrote:

It's a great time to be alive for photographers. I do wish there were a
third and fourth manufacturer who'd really push the big two.

You're right, a duopoly is only barely better that a monopoly. Canon and
Nikon aren't going to get into a huger price war without a third player.

Worldwide, Sony is currently number 3, Olympus is 4th, and Pentax is
5th, but Sony is very distant 3rd. Even if Pentax and Olympus call it
quits in D-SLRs, the market share won't all go to Sony.

Did I miss the 6D?

Yes.