(Im sure there was a dev blog somewhere so here's hoping Matt et al spots this one)
I don't use mySQL it's that simple. I use postgreSQL. I thought to myself hey come on it can't be that hard so off I went into the WordPress code.
The schema is a snap to move over so that's that bit out of the way and dropping in a slightly modified pgsql file for exsql was a no brainer. Some of the SQL statements I wonder about they're exact purpose but on the whole it's been quite easy to do.
Has anyone one seriously about doing this? The code wouldn't be that difficult to rewrite to accomodate such a beast. If you rewrite some of your SQL and make your date handling more generic I expect you'd be 90% of the way there.
I'm currently converting 1.0.2 so yell if you're interested. I'll prob retrace my steps and make it fully mySQL/pgSQL compatible as a proof of concept and you can decide what to do with it from there.