It's a very nice, clean layout, and I disagree with Andy, I think the green works well in the footer.
I think the main drawback for me is the lack of interactivity on the thumbnails. As a user I always want a little bit of response if something is clickable. I think that's doubly important in this case, since those photos might be mistaken merely for aesthetic embellishment, rather than for the interactive content that they are.
Also, your link identifiers are inconsistent. For instance, in the Tag section, they're brown text with a brown background with an underline on hover, but you use that same format to highlight the input fields in the comments section, which aren't links at all. The link in the post navigation section is in green with no hover state. In the footer, the links are undecorated with just a change background color for the hover, then below the footer the Pixel Boutique link is just a darker color with an underline hover state. I know this is a nitpicky detail, but having a definite link identifier really helps streamline a users experience across a site.
Still, a very good start.
A.