bill - 8:29 am on May 26, 2010 (gmt 0)
Red dots are used on the message level, but perhaps CSS would be a better way to highlight the new messages.
I'm not convinced a SlashDot type thread would work here. Even though there are some members posts I prefer to others you miss out on a lot with that type of system. I'd fear you'd have an entrenched hierarchy of Senior Members that might drown out participation from others. That's not the WebmasterWorld style.