I’ve just moved up to Wordpress 2.5 and it’s very impressive. There’s been a lot of nice work done to the post editor and the theme is a lot nicer.
The only problem I did encounter was that my wp-admin page was blank. Typing in another page, like wp-admin/plugins.php worked fine. gatewayy describes this issue at wordpress.org:
What I mean by this is that when your view domain.com/wp-admin nothing is viewable except for a blank page but if you view a specific page within /wp-admin such as /wp-admin/plugins.php the page displays properly. I have tried deactivating all plugins but the issue still occurs. Are there any suggestions for possible troubleshooting for a resolution?
Apparently this is because the dashboard page is now a widget page and some themes have incompatible widgets which can prevent it loading properly. If you’re having this problem, go to your /wp-admin/themes.php page and select the default. Apply it and all should be well again.
If you’re considering upgrading, it’s very smooth on the whole. I deleted one or two directories and then just copied the whole package over the top. There’s a handy list of compatible themes here.