I'm not really up on my Tribe fiction - are Trbies and Mechwarrior related? Maybe I just misunderstood your post.
As for Vengenace, you mean story-wise it's over done or something else? Personally, I think we'd have very few video games (and probably no kung-fu movies) if humanitiy's thirst for revenge wasn't mined for story telling material. Granted, it's an easy way to tell a story, easy to illustrate character emotions and motives (that guy wants to get that guy 'cuz he killed the other guy's uncle/neice/aunt/father/mother/teacher/neighbour/spiritual leader/shoe shine boy) and it's been told a million times, so I can understand the frustration with it's use, again.
Still, the story elements with the new Tribes, at least from what I read, should provide a really unique and rewarding single player experience. I mean, you get to play different characters through out different phases in their lives (ie. one level you're a young girl, and then another level you're somebody else. Then, later in the game you're the girl/woman again, but she's much older now). I don't know, I think it'll be neat.