I am really happy to hear that a games publisher is taking the CC License seriously for once, and I applaud you guys for taking that step. However, I would suggest that the Non-Commercial Clause that you have selected precludes 3rd Party Publishers from creating new derivative content. Before you take this step, you should probably look at how the OGL drew a lot of people to WotC's d20 products.
If you have already made this choice, would you mind sharing your reasoning?
Great idea for a game, in any case,