I think that it good to be space for member comments for each question for when we solve or want to solve, but we do not spoil it.
I think that if MikeMirzayanov make a such space we can solve a problem with several ways.
Thank for reading my comment
Spoj has that thing and most of the comments go like "AC in one go" and are not much helpful. So, I don't think such a feature is a good idea. As far as different ideas are concerned, you can always refer to the comments in the contest announcement blog or the ones in the tutorial blog.
AC in one go
You can already ask and see about problems in Announcements, Editorials and posts