I installed WordPress 2.5 last Saturday on all of the blogs I support. It had passed some preliminary testing on my development blog so I installed it. It is supposed to have increased security, better administrative panels, and the ability to upgrade plugins automatically. They say there are very few changes that will affect the plugins. It sounded like a safe upgrade so I upgraded. After a little testing I found that ImageManager 2.4.1 did not work at all. I am not sure when it stopped working since I do not use it often and I have alternatives.
While I was at it I did a little spring cleaning. I changed the blog to not use the www subdomain, changed the .htaccess file, changed the blog to use a more descriptive permalink, removed the register feature from the meta widget, and got rid of several old inactive plugins.