Sure, I love forking projects, for many reasons. Normally though, art assets aren't always the best fit for open source. Now I could come up with many examples where art is a great fit for open source, but it really comes down to wanting to keep the look and feel of the game unique. Another huge reason for not wanting forks is the inevitable community split, which again we can see with Xonotic vs Nexuiz.
Originally Posted by uid313