I don't mean to completely ignore your work, but I really thought that this was going to be something you built in Minecraft, so I got really excited. Because it'd be cool if people posted stuff like that.

Heh. I did too. Thought maybe it was a Minecraft skin at first.

Anyways, Tosh(iru):
I like it. A few questions and comments though:
1) What's with the bar on the 2nd and 3rd boards, but not the 1st? The bar towards the right side of the main cell.
2) The lightened boarder on the on icon is VERY hard to notice. Instead, maybe use a diamond block to indicate new posts?
3) Nav tree arrow is hard to notice. Personally, I'd try a different color or lighten the background.
4) What's the collapsed category icon look like? You only demoed the open one.

I'd also suggest getting rid of the redundancy in the title. You have a banner image with the name of your forum, and then the name of your forum next to it. It's cluttered and unnecessary. I'd stick with just the Minecraft block logo and keep the actual text next to it, but you can go with no text at all and leave the image as-is with the warped text. Your call.

New update: i5.minus.com/iXEMf8c1jK1Bo.png

Chris:

1) That bar was a minor mistake that I forgot to take out. Fixed it now.
2) I don't even play Minecraft so I had to google what a diamond block was, haha. I instead used a stone block for the off icon. Tell me what you think.
3) I made the arrows on the nav tree a tad bit darker. I might jsut revamp the whole thing later on though.
4) I showed the collapsed icon now and I also redid the whole thing to something a lot simpler.

Lucifer:

Haha, yea I don't even play Minecraft but some of the artistic game is really rad. And yeah, I fixed the logo.

Sneaky you are...drawing all us gamers in with your title

Looks better. Just noticed that you have two different gradients.