Apparently, in Swedish, the name 'My' would be pronounced like the English word 'me'.
Compare close front rounded and unrounded vowel sounds:
Rounded: http://en.wikipedia.org/wiki/File:Close_front_rounded_vowel....
Unrounded: http://en.wikipedia.org/wiki/File:Close_front_unrounded_vowe...
It is however the pronounciation of the greek letter μ (in Swedish). So it could perhaps be construed as micro-SQL if you wanted to.
Monty's official explanation is that it's named after his daughter, but I'm sure the double meaning with the English word played in as well (and perhaps even the micro-prefix).