USA Today has an interesting post on their Community Center blog about their decision to post the latest comments on articles and blog entries first.  Most blogs (including this one) post comments in chronological order instead of reverse chronological.  Here is USA Today's explanation of the decision:

As development continued, USA TODAY considered the audiences and found the story audience faced more of an adjustment at launch. Beyond debating the order of comments, this audience was new to the first step in the comments environment — commenting itself. This adjustment strongly favored putting the latest comments first. When you wrote a comment and submitted it, that comment immediately appeared at the top of the list, directly below the submission box. The animated effect showed the interaction was easy and successful, rewarding to anyone stepping into the world of commenting. Keeping the latest posts on top also complemented the way editors handled stories. Just as editors overwrote stories with updated versions or weaved the latest details into stories' opening paragraphs, the latest comments followed along.

I understand the logic being used here but I think in almost all cases a first-to-last approach is best.  Why?  Because it makes it possible for readers to comment on what others before them have said and to have an actual conversation with each other about the story. 

When you post from last-to-first, readers can't really follow the discussion and you typically end up with random, disconnected comments (like you see on MySpace pages).  This approach will lead to 100 separate comments from readers that sort of exist in a vacuum.  The real power in commenting is in people building on each others thoughts and actually getting somewhere.  

What do you think?