I do think that lately there are so many forums and DDL sites around its hardly worth making one anymore. In my eyes a lot of them can be merged together.
To be completely honest, and this is the same reason i dont own a forum/ddl site, you need to go down litewarez's path and make something as unique as it can be. It does mean if you dont know php, your gonna need to learn it, but hey, im sure you've faced tougher things in life, and a lot of people here are more than willing to help if you get stuck.