Not a bad idea to be honest. However what if the user would like to reply to a new person, or bring up a new point that he or she would like to be differentiated from all the rest of the previous posts?
I do not think that if you are creating quality posts and have a reason to make another post in the same topic, you will be considered as a spammer. It all depends on the actions and style of writing for every individual. You always have access to the "Edit" button if you want to ever add more to your previous post.
I am talking about back to back comments here. 🙂
Oh, well yes, then it would make much more sense. (By the way, love the Android smiley 😉)
I wish the new forum would be announced soon, the community has been waiting for some time now. However, I guess it's theymos' call, not ours.