I am thinking that some sort of colouring of usernames and/or comment borders would be useful in order to quickly denote project role or user group. This would especially be useful on Atlassian's instance or JIRA in order to quickly pick out the comments from Atlassian staff and the reporter from all the other chatter in the comments of an issue. I have seen this implemented on various discussion forums in order to denote experiance/contribution level of users and have found it to be very useful. This would be of benifit to me in my instance of JIRA in order to highlight comments from management and also comments from customers.