Bah! Stop making sense! :)
Actually, thank you for the very nice response. I understand completely, though I do wish Blizzard could provide the info needed to do this. :)
Is there enough communication between Omen clients that, if I tell my client "I'm the tank", then when another client sends an AGGRO warning, it'll tell my client which will say "The stoopid Mage is approaching your aggro on Mob Foo" or something to that effect. I know *I* can understand that it's a warning, and that I might lose aggro at any time without said warning, and that it's not 100% reliable. But I'd think it would help considerably.
That said, yeah, 'til Blizzard can directly tell the addon what everyone's *real* threat level is, making a tank threat warning is very hard.
Thanks again for your response!