I was trying to install WordPress 3.0.1 on my MAMP localhost but the 1st install screen came out a blank page. Error log reported:
[30-Jul-2010 14:29:35] PHP Fatal error: Cannot redeclare class wpdb in /Users/me/Sites/buddy/wp-includes/wp-db.php on line 53
It installed fine using 3.0.
Anyway, just wanted others and the WP team to know about this.