The challenges stuff sounds really interesting, whether or not it increases activity, as something nice the board is doing for its users. Of course when it hits off it must be very fun. I went over there to take a peek -- flash fiction? What a good way to just get people writing.
The trick with writing, I think, is to keep your calm no matter what's going on in life -- if you're unruffled and comfortable enough that you can write anytime you want, then nothing can stop you. But that's hard to do.