a) Swap the logo & twitter bit around. b) Bit more contrast on the navigation. c) Make the difference between items/whatever more prominent, like on the PSDtuts site.
Otherwise, that’s really nice!
I go approve that points.
I think you are in the right direction, but the alignment is a bit off to me. You could try aligning your tagline to the left on the same grid as your content. Also, in your footer, the text in the bottom right is better placed when aligned together with the guideline of your content. This can create a bit more structure into your design. I like the looks of it so far so keep us updated!