I just went through the automatic upgrade process twice. Both times it tells me that my upgrade has been completed but WordPress dashboard is still showing an upgrade link and saying that it's still 2.5.1 with a link to update to 2.6.
I've logged out and back in, even logged in on a different computer to make sure it wasn't a cache problem or something. Same thing though.
Any reason why the upgrade goes through the whole process and says complete even though it appears that it's not?