At first, the interface was a little bit confusing - but with the arrow conventions it became quite clear what did what.

It's quite intuitive after the initial "Whoa, what is this?" but I'd almost venture that the bottom menu is nigh-redundant and could be worked in much like the Photoshop CS3 menu instead - another possible level to be extended or detached if need be. Having the messages a forced click deviates from the other rollover behaviors.

Would love to see a delayed rollover - 900ms or so - for the messages as well.

Quite nice actually. Readability on the vertical text though is lacking on one of the libraries/images - should be able to override the text being on the side... still very nice indeed.

Would love to see a pixel font variation as well. Silkscreen is a freeware font, I think.

Any word on customizations?