The odd point i would add is that Amazon are betting on it with Aurora. While Aurora is not really MySQL, the fact that they decided upon the MySQL API rather than PostgreSQL really says a lot about the market penetration of MySQL and that its truly got some life left in it yet.
Personally, I love PostgreSQL, it's my preference in terms of a db engine...but i have to agree with a lot of the above comments (excluding pt 4 about cluster - thats a world of trouble in my experience)