very nice mate, i like it. the menu on the side is especialy nice mate, you did a brilliant peice of work doing those tab/menu options.

Not overly fussed on the atom logo your using in the top left corner of each content box, its not that crisp and not sure if it melds properly. A nice plasticy or glassy button (flat top not domed) would look better imho.

the spacing is a bit large for my tastes, but that may be the style your going for.

You have a problem with placing that graphics behind the text on the content boxes. you can't tile it and you cant strech it, so for each non-standard sized content box your going to have to do a custom one. thats going to increase the download size. i would suggst changing it for one you can tile or fade it to a solid colour so you dont have to have large downloads.

overall mate a very nice job.