Hey Silas, looking really great! I have a few thoughts...
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1. The grey in the column headers bar looks a little out of place. Is it possible to make it some shade of blue but still stand out sufficiently?
2. I think there needs to be a little more contrast on the command buttons to highlight them a little more.
3. (not shown) In artwork view the pale blue highlight around the selected picture is barely noticeable.
4. The last.fm button looks great but i'm not sure if its stands out too much with the red or black background. It doesn't quite match the feel of the other buttons next to it...
5. The menu's are all still grey, perhaps they should have blue backgrounds to match the skin?
6. The new tab and forward/back navigation buttons are maybe a little dark.
7. Are you planning on allowing skin windowless borders? What you have done currently in that it maximises space and still allows aerosnap is great but visually i'm just not too keen on it. Personally I have MB always maximised or minimised so love windowless borders.
Hope none of this seems like criticism, its not! The skin is already looking fantastic, i'm just nitpicking...