I updated to the latest version as well, about an hour ago… then all hell broke loose… literally the WP broke..nothing would come up. I host my own WP through my WHS [windows home server].. so I went and got the previous version I had, 3.0.4 and then went to the folder which holds my WP files and deleted all the files except, wp-content folder & replaced all the files. Bam! every thing’s up and running… When I log into the Site-admin.. it says it needs to do a Database update, which I was like Oh-No~ but its ok.. once that was done, everything was back and working correctly. I am seeing that there is a Update available for 3.1 but I am not doing it again.
Good luck to everyone else.. I knew I shouldn’t of hit Update Automatically this time because I read yesterday others were having these issues.