Andrew, that would have been +1 insightful if MySQL was actually faster or easier to install and use.
And that's not me making that up, that is visible from published SPEC results. (http://www.spec.org/jAppServer2004/results/)
I happen to regularly meet the Sun guy that does all this testing (http://blogs.sun.com/tomdaly/) and know for a fact he doesn't have a bias. He actively works as coder on both, to try and make them go faster, regularly submitting patches.
Speed wise there isn't that much between them, though Postgres still has a massive edge on 4 cores or more, MySQL can't take advantage of those.
Also, on Linux it is the same, but the Windows installer for Postgres is actually better than MySQL's. (which might be taste)
The only thing MySQL has going for it is the enormous amount of books written and the ubiquity it seems to have because of LAMP. Which is strange because with the dual license MySQL isn't exactly free. (as in speech) Plus there are lots of options you have to pay for, like a thousand Euros for online backups in InnoDB!
So no, Postgres won't eat too much into MySQL's market share soon, but that has nothing to do with speed, technical ability or ease of use.