[Ygorl]

My feeling is that threats, gloating, and unfocused ranting are okay as long as they don't actually provide any information about the game.
"I will destroy you all!" is probably fine, as is "Mineral planets are the best!"
"Wow, Mictlan just took a pounding" is no good, though, as would be any sort of conditional threat.
Since there's such a fuzzy line, it might be best to refrain from messages altogether. We can gloat or moan here when we're divine or dead.
Dogs be free!