Luckily I tested 2.5 on my own PC and not live on a site, made sure the plugins were up to date, used the WP automatic Upgrade plugin to see if it makes things easier.
And it did, everything backed up, deactivated, installed and reactivated with the minimum of fuss, except the Viper’s Video Quicktags that I use for the YouTube videos, which couldn’t be activated, quick squizz at their site, ah problems with the comment form plugin I’m using which I’d overlooked in the plugin upgrades, once that was installed VVQ worked fine – I see VVQ has been upgraded.
Great, until I clicked around to make sure everything else worked and I started getting the 404 error page instead of the categories – Advance Permalinks plugin has gone totally tits up, where it worked perfectly with 2.3.x.
Now with a bit of messing about I could get the categories and posts to work but then the pages flagged up the 404. This plugin was a god send after I moved the blog from it’s own directory in the last version of the site, keeping the blog post uri as /blog/date/post-title/, so much so I used it on another site when I moved it to being run by WP.
And is that the moral of this story? – don’t rely on one plugin 🙁
Looks like more hacking about is required, oh happy happy joy joy 🙄