It looks pretty cool I think, I do agree with Wildhoney though that you're wasting some space there, it's above "the fold" and people will look at it all the time, maybe add a short description of the site there, and hide it for people who are already logged in and know already.
I was having some problems with links though, for instance the about page doesn't lead me to an about page but just the home page, same thing for the "more.." link at the top right about the competition. That definitely needs to be fixed, broken links will never make your visitors happy..
Yeah I have to agree with everyone here and say that you don't want to waste that sort of space. When a person first views your webpage that will be almost at eye-level and needs to grab the viewers attention. My advise would be to have a bit of a shuffle and perhaps get your site/company logo in there (yes, I know many sites use this idea but its used for good reason). Another idea would be to put something in there that is useful to frequent visitors to the site. Overall I quite like the design though with a few tweaks I think I'd like it even better! (: