I am writing a blog post for a class, and need a word that describes all the students who have yet to post.
Therefore I pose this question to (anyone who has not yet written their blog response): blahdy blahdy blah?
Therefore I pose this question to pending bloggers
That is, using the word 'pending' as an adjective ...
From Mirriam-Webster: 'happening or likely to happen soon' (http://www.merriam-webster.com/dictionary/pending)
From dictionary.com: 'about to take place; impending.' (http://www.dictionary.com/browse/pending)
Why not potential bloggers?
Having or showing the capacity to become or develop into something in the future: a two-pronged campaign to woo potential customers
(Of a person) expected or expecting to be something particular in the future: she showed a prospective buyer around the house
Oxford Dictionaries Online
I think that for a Web site, lurkers might be the best option - it's jargon, though. Or you might try bystanders.
That said, I would not make too great an effort to find a single word.
I take it you are looking for something fairly concise.
I pose this question to the as-yet uncommitted...
I'm thinking of those who haven't yet responded to a poll.
When your students are used to this, you could leave out the "as-yet" part.
What about the word tardy? As I understand it, the OP would like to remind the students that some of them have not yet submitted their contributions to the blog. So, the teacher might say to his/her class, "Would those of you who have been tardy in posting, please do so as soon as possible".
Tardy : Slow in moving, acting, or happening; arriving or doing something late. Merriam-Webster's Learner's Dictionary