After reading this reply, and being a mySQL user, I naturally went to read much of the refered to page
(it's very long).
It's a very interesting sequence of posts and responses, not so much because it was in any way conclusive on the "Not MySQL" front but rather because its a good lesson in how things change. It's a conversation that started a year ago and still continues, and shifts subtly as the various systems it discusses have changed over that time. It's also a good lesson in how inteligent people can have radically differing opinions because of the the questions they think are important to ask, and the problems they think are important to solve. I highly recommend it, but again not because it "proves" that MySQL shouldn't be an option.