I just looked it up and it seems DW's comment limit is 10,000 on an entry (and after 5,000 every comment gets a 'human test') so I have a suspicion the 3SF may reach it. >.>

Also if it reaches the limit on still prompts then people can no longer fill older prompts or comment on minifics! *gasp* (I think that's why most prompt memes call it and make a new post at/around 7,000 comments?)