WordPress 3.2 beta is out for testing and with it comes several requirements.  The two notable requirements are PHP 5.2.14 or newer and MySQL 5.0 or newer.  I will likely move to 3.2 for wp-SwimTeam development once it is released and I’ve done some testing with it.  I’ve been running under PHP5 (5.2.14 and 5.3.x) for a while now so I don’t see this as an issue but it might be for people running on older web hosts.