;-) Now this is really getting there.
:-) In the first screen, I see that the window gadgets have just a taste of 3-D, and not too much. It looks like OS 2.x, updated. Very new, yet very familiar, at the same time.
On the tools dock, there's an icon called "Access." Does this relate to the new file system, or is it just some application or other?
:-? In the second screen, I see YAM, which seems to have been updated. It seems that the right edge of the "For
ward" button is chopped off, but that's just due to the window not being wide enough to include it. It it using MUI, here?

On the third screen, I agree that the sizing gadget makes the right and bottom borders seem a little awkward. Maybe it's just that I'm used to borders that wide having scroll bars in them, and they're absent, here. Maybe the right and bottom borders could be thinner than the sizing gadget, until the window reached full size, then the sizing graphic could become invisible, but still functional, until the window was reduced to less than full size, again. On the other hand, that may confuse people who weren't used to it, yet.
The 3-D effect is still spot-on, though.
;-) Screen Four shows IBrowse running in a MUI window which looks just like the intuition windows. Appropriate. Notepad seems to have gained a few buttons. This is a welcome change, since one now needn't use the menu all of the time. On that note, I wonder if the Magic Menu functionality allows the user to call up menus with the touch of a single key, as Windows does with the alt key? I've gotten used to that; it's nice to just keep going without switching contexts to the mouse so frequently.
I like that the information window includes graphics, here. Very intuitive. The graphic foreshadows the flavor of the message, sort of the way I've taken to abusing Amiga.org's emoticons.
I wonder if the user can define his own graphics for this?
:-D With Screen Five, I see that the active window is a little lighter shade of blue, and that the scrollbar buttons have a bit of 3-D shape to them. All the buttons have slightly rounded corners, now. Cool.
Two minor niggles: the checkmarks are still un-anti-aliased, flat, (vector?) images, and the sizing gadget seems to be flatter, now, or maybe that's just me.
On the plus side, again, the brushed metal look seems to have been toned down a bit, by reducing the range between lightest and darkest shades. I like it. It's good to break up the monotone gray with a little texture, but not so much that it distracts from the elements or text in the foreground.
Overall, the implementation here is done well, but maybe the blue is a little too pale for my taste. Something between the two might be best.
Also of note, In the system drawer, I see tools to start, stop, and restart the USB bus. That's curious. And color me dense for not noticing right away, but the boot partition is now called "OS4:" by default, instead of "Workbench:" That seems appropriate, too.
All in all, this is shaping up to be a very nice default look for AmigaOS 4.0, out of the box. This is what the new customer will see on the display model in the stores, and one never gets a second chance to form a first impression.
:-) Hyperion can be proud of this.