That approach sounds good to me (and is actually somewhat similar to my suggestion a while ago of having red post icons for new threads, orange for new replies to old threads, and yellow for old everything--back in the days before all these suns). I think the sticking point now is whether or not Scream can determine which threads are new efficiently in the current code.
Bill Dimm,
MagPortal.com - [:red]free feeds for your site.