There is an interesting article with A First Look at Longhorn. Lots of screenshots and some commentary on some of the new features from the latest build (4074, WinHEC version).
My opinion on this is pretty much as follows. Looks mostly like XP with a black skin. Many of the changes appear to be cosmetic, and some major components are lacking in any really exciting upgrades (ie: IE has pop up blocking (which warns you that it might not work!), but no tabbed browsing or anything else that looks remotely revolutionary. Some things are just wacked, like the sync manager still uses the windows 95(!!!!) offline webpages icon, and the icons still don't seem to be scalable.
The 3D avalon mode looks pretty swanky, but nothing that hasn't been in OS/X for 4 years and Linux (in various forms) for a while. Basically it's dropshadows and a nifty thumbnailing alt-tab mode. All this requires a fair amount of hardware of course. Of course, sometimes features like this new alt-tab are far worse than the tried and true classic. Anyone using the new alt-tab replacement that came out for XP, which thumbnails and gives you huge ass icons in your alt-tab list? Didn't think so.
Overall the interface is pretty similar to XP, but in some places it looks far more cluttered, a step backwards, not forwards, to me. Of course, this is still pre-beta, full of debug code and un/half-implemented features, and the final product is still years from release. It's still interesting to see what's coming up. Based on this though, I'm not chomping at the bit yet.
