Comment by markjaquith

We don't currently have any interest in moving to a database abstraction layer. We do, however, allow you to drop in a db.php file that can replace the core database portion. That's not abstraction (you'll have to rewrite any MySQL-isms to be compatible with your DB of choice), but it is an option for people who absolutely cannot run MySQL. Microsoft wrote a WordPress plugin to do something like that: http://wordpress.org/extend/plugins/wordpress-database-abstr...