It's hard to say this without sounding ungrateful for all the work people put into this. And I really love WP.
But I just dloaded and installed 2.5, and was really disappointed.
There were a lot of improvements, but I have two main concerns.
-Poor backwards compatibility with theme/plugin.
Granted, I've only spent little time on this, but my theme doesn't work and the plugins has glitches.
-Poor admin menu.
This is more important though, I am really not pleased with the admin menu. It is too simple, and I find that it takes time to get the complete overview on each page. The colors don't help either. It's cool if it looks good, but this is the back end of my site, and therefore I just want it to work as efficiently as possible.
I fear that I will have to use a lot of time and effort to update my site. But I also want the new improvements and the security. I don't want to be stuck with 2.3 for ever. Help?
One last disclaimer: These are my personal opinions, I don't mean to start a flame war, and I know that 2.5 is still in beta and I that I haven't tested it for a long time. I just had to say it.