A small exclamation mark link has been added to the bottom of each comment, left of the "posted by" line. This link appears to logged-in users. This will probably function like the Ouch!!! command that was used in the old version of Toledo Talk.
To explain the usage and possible application of this command, I'll paraphrase from the July 2006 explanation of Ouch!!!:
A method was added that allows logged-in users to complain that a comment is inflammatory. A user can only complain once per comment. Trying to issue a second complaint causes the user to receive an error message, telling the user that he or she complained already for that comment.
After the complaint has been issued for a comment, all that happens visually for the user is that the page reloads with the comment being complained about appearing at the top of the webpage, as if the user clicked on the comment's permalink.
A complaint is registered in the database. When a comment receives 'X' number of complaints, the background color for that comment change to a light red, indicating to everyone that it's a comment not worth reading.
This is not meant to be used because one user simply disagrees with another user's viewpoint. The flag command is meant to highlight obviously offensive or troll-like comments.