For the main site (non-forums) it has quite a nice layout, but I'd enjoy to see it a bit 'smoother', one recommendation that doesn't break any browser compatibility is CSS3 transitions, elements like the navigation for the height expanding, the menu hover could slowly change, this can be accomplished with something along the lines of:
-webkit-transition: background 300ms linear;
-moz-transition: background 300ms linear;
-ms-transition: background 300ms linear;
-o-transition: background 300ms linear;
transition: background 300ms linear;
If whomever codes the site isn't familiar with CSS3, I personally use a tool to remind me of cross-browser compatibility css-tags called "CSS3 Generator".
Additionally the menu I'm not quite found of the -amount- of padding it seems to have, it seems obnoxious.
Other than that, it's looking nice! Keep up the good work and thanks for reading.