I was just trying to update my WP from 2.9.2 to 3.0. I first updated all the plugins used (AddToAny, Advertising Manager, DMSGuestbook, Google XML Sitemaps with qTranslate Support), then deactivated them and, naturally, pulled a full backup of the db and the existing WP files. I also deleted the "upgrade" folder under wp-content, that's what helped me get through the update on the other WP blog I'm running. When I hit "update automatically" the update page showed the following message
"Downloading update from http://wordpress.org/wordpress-3.0.zip."
and then nothing more happened. The 2.9.2 is still working properly as far as I can see it. My provider is 1&1 Webhosting if it helps anything. Any advice is much appreciated, thank you! :)