Perhaps you could do something a little bit novel allow all comments to behave like a chat room:
fixed size comment area, with a scrollbar that starts at the bottom, when you scroll up you load earlier comments dynamically?
That way you can always see the most recent comments in the discussion, and easily scroll backwards through the history to follow a conversation.. scrolling and loading dynamically is a lot 'lighter' of an interface than the frustration of paging. (that's my own opinion, not backed up by any usability studies)
fixed size comment area, with a scrollbar that starts at the bottom, when you scroll up you load earlier comments dynamically?
That way you can always see the most recent comments in the discussion, and easily scroll backwards through the history to follow a conversation.. scrolling and loading dynamically is a lot 'lighter' of an interface than the frustration of paging. (that's my own opinion, not backed up by any usability studies)
just like people expect from a chat room.