"Would you learn MySQL for a new job? Or are you a die-hard, this is my platform kind of person?"
I think we would all learn whatever we needed to for a new job. I learned SQL initially via using the Mainframe version of DB2. The next job after that required me to become fluent with SQL Server, Oracle, DB2 that ran on OS/2 (Yep, I'm that old), Informix, Sybase and probably one or two others that I don't remember. Oh, and some BTRIEVE too, which isn't a true RDBMS, but always fun to reference. My current position has required me to become much better with SQL Server, but at times I had to work on skills for Oracle, too. Oh, and on Netezza systems - that was, umm, exciting.
I realize the answer is somewhat off topic, since Steve's talking about MySQL (which I've never messed with). But his question I quoted above is to me an interesting point of discussion.