I have three scenarious where I think that some assistance would really help make the blogs successful.

One is on a social/friends/School site where each user has a blog.  The Blog Admin would be able to enter topics like:

What I did last summer, What are my new years resolutions, How was my week.
For school, assignments could be given to bloggers, with deadlines.

Second is an enterprise intranet: I work for a city, and it would be useful if the Blog Admin could act a bit like an Editor and enter topics, and set/suggest deadlines.

Third as a bonus, this could help bloggers set their own topics and deadlines ahead of time.

This functionality could be worked out exclusively within the Blog software, or it could utilize the Announcements/Events modules to notify the bloggers of upcoming deadlines.

What do you think?

I don't know.  IMO that seems kind of like a forced and ridged (sp) way to use a blog.  Blogs, to me are supposed to be more of a personal kind of thing and not controled by some administrator.  More of a diary kind of thing.

What you are talking about seems more like a story or article submission kind of module.  Something like what a newpaper editor would run where s/he tells the reporters to write on some topic and it better be done by 2pm or you loose your job. :)