The WordPress Development blog has a “Sneak Peek” of the new admin interface, which (finally) goes some way to explaining the reasoning behind the new design.
While some of what’s being said about deficiencies of the current version has some truth about it, I remain unconvinced that the solution is actually of any use. I’m not greatly bothered about the layout of the Dashboard, which I only glance at now and then anyway. While I think that splitting the menu into two with some allegedly less-used options hiding over to the right of the screen, but what I really can’t deal with is the destruction of the Write page, which, as the post says is the most frequently accessed part of WordPress. As I’ve mentioned before, I’m not at all happy with what’s been done here, and like a few other people, I’ve been baffled about the removal of useful functionality, and an apparent love affair with scrolling. Well, here’s the reasoning:
…its myriad options can be overwhelming. The new write screen only displays the information that you’ll use most often. It displays the most common fields in a way that makes posting incredibly easy. Additional options are hidden away until you need them. The new Write screen anticipates the natural flow of the way you write, and is smart enough to remember the way you left it so that your preferred writing environment is always quickly available
Right. Previously, I got to decide which information I used most often. I could hide options I didn’t need. I could (through plugins) easily add extra options to the nicely configurable sidebar and put them in the order I liked. With 2.5, all that is gone. The change appears to have been made in the name of “making it easier”. Yup. For me, the new interface involves a lot more scrolling up and down, which is more effort, and I’m more likely to lose the thread of what I’m doing. This layout really doesn’t work for me (and yes, I’ve been testing it locally). In short, it’s bad.
Quite apart from disliking the change, I really don’t like being told that something I use without any effort at all needs to be
broken improved to make it “easier to use”.
One other problem with the design can also be seen in the Development blog post – the vertical spacing of items in the management pages is huuuuuuge. So even if you have a high resolution screen, you’ll see less information at a time, which means yet more scrolling up and down to get things done.
There are also some minor issues with one of the colour schemes in the admin interface – but I’m sure that can be easily fixed, so it’s not a show-stopper for me. I’m not a fan of the new “fresher and lighter” look – for me, it lacks enough contrast to make information stand out, which the current colour scheme manages quite well.
Anyway, WordPress 2.5 is now at the RC1 stage. If you’re thinking of upgrading, I strongly recommend trying it on a test copy of your site first. You may love the changes, but for me it all seems like a step backward, and I won’t be upgrading Losing it in a hurry. If someone with coding skills produces a plugin to revert the Write page to something more usable, I may change my mind, but for now I’ll be staying with version 2.3.3.
 And with the default fixed-width setting, they can be along way from the rest of the content if you have an even moderately high resolution
 Easily changed, thanks to this plugin