I've started a page that catalogues applications that use or require MySQL to operate: OS X Apps that Use MySQL. I'd really like Apple to include MySQL as part of the default install (I'm sure they can come to an agreement with MySQL AB over licensing if they really wanted to) but until that time it's up to the end-user to do it for themselves.

My thinking is: the more quality reasons to do it, the more likely users are to make the effort to get it done. If you've got an OS X app that uses MySQL, drop me a line and I'll add it to the page. Discuss