I personally think my major wants would be:

1. I'd like to see icons for all the tools. The option to choose whether or not to have the text accompanying them would be warmly welcomed.

2. I think if colours are going to be used to show automation state, it should be the outline colour of buttons, not the overall solid background colour. I for one, really like the fact that I don't have to stick with a boring, grey, uninspiring interface – that all the colours are currently customizable! Blender set up black with green controls looks awesome and I find colourful interfaces inspiring to creativity. A lot of people find the opposite. If it were only the outlines of buttons that changed colour, we would still have the option of using colours for what they are currently used for, that is, making it even clearer what kind of button it is! Also, the colours used for such outlines should be customizable. I have always prefered red to indicate automation, as this is generally used in audio applications for instance, but it also seems more intuitive because red means 'don't touch' or 'danger' to me, whereas yellow just means 'yeah, go ahead and fiddle with it'. Green is however a good choice for keyframes, though going with an overall green layout, I would prefer yellow! :P

One other thing that has not been considered, is how python buttons would fit in with all this? I'm not sure whether python buttons will be able to be animated in 2.5, or whether drag-and-drop would be a possibility, or even how python tools will be integrated into blender. I'd love to see them as panels in the tools window, having the option to run them almost like plugins, where they don't have to be stopped and started all the time, but could remain running as extra functionality until it is decided by the user that they should end. If done like this, python buttons could well be automatable, tools could be written that fitted in with the interface of the rest of blender, and some tools could be set to start and stop with blender each time it is run if the user uses them a lot. Those scripts that perform some action could register a button for themselves in the user interface somewhere. That way, they would appear to be action buttons written into blender itself. (although perhaps they could be marked as script buttons by the outline colour) This is invaluable to making python features easily accessible from the interface and solves the problem of having to keep switching to the python window or scrolling through menus to choose a suitable script every single time you want to run it! The same multiple-object functionality needs to be implemented for python too to a certain extent – how many users want to have to go through 300 monkeys going through a menu, finding the right script, and running it for each one? Wouldn't it be a lot simpler just to select all 300, then just click on a suitable button, put there by the script having been registered into the interface?

To me this means that this new interface is not going to be on 2.5. 2.5 is going to do the necessary retooling to make the new interface possible, but not actually implement it yet.

First: I have some doubts of removing floaters from 3D ui (if I got it correctly that the properties will move to the button bars).

Since the floaters are transparent, they do not obstruct and are quite easy to hide/move (N – key) — they are beneficial by being nearby — you keep the mouse in 3D window and as such the movement and tweaking is cheap considering the mouse travelling and aiming time. (Rotate the view, tweak, rotate again)

Second: the scrollbars. I have never missed them and at least on the mockups they only add to the visual clutter. A compromise could be made — maybe some rectangular 3px wide strip on the right side of whatever you want to scroll.

Also, please do not forget the mouse aiming — I fell in love with the current UI when I saw the Quit dialog: it appeared under the mouse and it went away by moving outside of the menu. I do not know how the sphere creation example could be made with this tweaking possibility while keeping to that local-mouse convention.

My (three) cents.

http://lacquer.fi/images/conduit_060405_1.png

I especially like the option to make annotiations (here: tree foreground, sky matte)
and that color nodes have the respective color

Several functions in Blender ONLY have hotkeys: they don't appear in a menu or a button. Just in a hotkey. Also, buttons don't tell you what the hotkey is. If a function is JUST hotkey then the chances are loads of people don't know about it.

Also… how about a new panel called Help?

as for difference – i strongly disagree with the notion of something – especially an interface- being different for the sake of difference! that adds nothing and makes it unintuitive for everyone coming from elsewhere. switching the positions of the gas, brake and clutch from car maker to car maker doesn't make anything better or easier for anyone.

if it's different, it needs to be because it is BETTER.

jin