Movable Type 2.5.1 is now available. It adds an MTElse tag, which could be useful to template hackers. It doesn’t overwrite unchanged files, which means RSS files on ETag-enabled servers won’t be mistakenly marked as changed (and therefore won’t be redownloaded by ETag-aware news aggregators) every time someone posts a comment. If you upgraded yesterday (like I did) and are experiencing incredibly slow rebuild times, it’s a bug and it’s been fixed, and you can just redownload MT.pm and put it in your mt/lib/ directory. (Thanks, Shawn.)
It also includes an updated RSS 0.91 template, which you will need to upgrade manually. It produces valid RSS now, thanks to a new no_colon attribute on the MTBlogTimezone tag. However, you will still get more functionality by upgrading to RSS 2.0.
