My first impression of the site is mixed.

Good points:

General layout of the site is quite good.
Ability to edit articles, add games, add screenshots etc etc.

Bad Points:

There's no single page with all the different forums listed (or that i've found) it's just a single page of all the topics thrown on to one page.
On some forums there is no navigation you have to use the back button on your browser.
Font on the left border looks awful.

The site is new anyway so i'm sure the issues will be fixed. 
I hope that the Giant Bomb site and it's community continues to evolve into something awesome!