I'd be interested, but like Kristen, no more than the number of days in the month, and, for me, no posting several dozen images at once. One image, one day, every day, or give it a miss if you can't post that day, nobody will think less of you.
I would also suggest that film users be given a separate thread since they wont be processing one at a time each day, I hated the way film shots overwhelmed the gallery on the day they were posted during the prompts challenge. If they go in the same thread, posts will roll off the page to the next or the next, and its not fair to those who are posting one a day.
Prompts: well... having said all the above, if its prompts like last time, I won't be playing. it was far too restrictive and although I made it for all except one, it felt more like work, than fun, in the end. It was fun at first, but by halfway through I seriously considered forgetting about it (as I think some did).
So how about doing a single (a single anything, just one image, one day) in October, since September is half gone, and have a good think for the next couple of weeks about how it should run. I think starting it in the next few days is too rushed, and not enough planning to go into it.