This blog is currently running on WordPress 2.5. I took the usual process > download WP 2.5 installation > unzip in my HD > ftp all the WP2.5 files into domain host > upgrade successful. I skipped the whole process of deleting the previous wp-admin files etc. and went directly to upgrade.php. Looks good so far. The major changes happened in the WP dashboard.
I’ll write a full review at Rotorblog. In the meantime, just take a look at the screenshot of the new WP2.5 dashboard.