I much prefer the flat shaded. The other one is hard to read for me, and the eye and ear merge into one. In fact, those ears could probably do with being a pixel further back, they're very close to the eyes right now.

I have to admit, I was expecting something more conventional. ^^;
I like to have multiple documents open at once so I tend to prefer a regular window-based setup. Just now, for example, I had my different loops open in different windows in photoshop whilst I animated.

I agree with Jad, this doesn't strike me as somewhere I'd like to work, especially in relation to swapping between other software that I use during the task.  I loath Zbrush because of its very custom GUI, and unfortunately I can't imagine myself using this in its current incarnation because of the fruity GUI.  It makes more sense in zbrush, LightRoom and Aperture (software which works in full screen mode) because you're working on something very big and detailed. The opposite seems true of pixel art, where I tend to prefer my windows small to medium size.

I think I expected something closer to Microangelo: http://www.microangelo.us/icon-tools/icon-editor-example.asp

Is there something bad about PTK?

I've never used it, but people on the Indiegamer forum seemed to gush about it, and it sounds pretty good in general.

Another request for a mac version. There are a lot of people itching for a usable pixel editor on mac!

Try to copy Photoshop's shortcuts and main interface as much as possible, as it is regarded as the 'standard'. Things like zoom, scale brush, etc are in a lot of different programs now.

Please focus on a clean and modern user interface most of all, actually.