I was hoping not to get into a detailed design critique-- but go spend some time at http://sortfolio.com/ or http://smashingmagazine.com/ and see if you don't agree with me.

The concept behind the site is a useful one-- I think you could make something of it. But you need to be credible to your target market (designers).

(PS If you really do want a point-by-point I can do that).