Discussion2 rolls on... the most recent addition to the system is in-place comment posting. Essentially, little dynamic ajaxy slideout boxes to post directly within the thread, without going to a stand-alone page. This is great because you don't have to lose your place within the thread to post.
this functionality is currently only available to paid subscribers, and several hundred of them have tested it out already. We still need to make it look pretty and add a few minor things (like the CAPTCHA for anonymous posting) but it's almost done.
Also worth noting is that logged in users can click on the 'Score' field of comments to view the moderation information on the comment. This information was previously not visible within D2, unless you navigated outside the d2 system (opening a comment in a new window did it). I doubt most people really care about this info, but it's available.
We also have one (perhaps minor) thing to get in... right now if you visit a comment directly via a CID link you can navigate within that thread, but navigating 'up' the comment hierarchy results in a new page, and a new discussion... this makes context a pain to maintain. So pudge is going to change that page to display the parent posts in an abbreviated format. This will mean that you can climb back up the thread easily, even if you entered the forum via a link deep into a thread.
A few minor items left on the todo list (keybindings for threshold changes... maybe press 'r' to open the reply slideout from the current comment, and a bunch of small design issues to make the threads a little more visually clear and easily navigatable) and we're ready to call D2 finished.
We have no plans to remove D1, so those of you who hate D2 are welcome to stay on the old system, but obviously new moderation tools and whatever else we think of will be attached to D2, not D1, so you've been warned ;)