I think terrorists should be a disaster in Sim City. I mean trying to counter hijacked planes and bombings, that sort of thing would be cool.
Haha - that may affect the ESRB rating a bit. Sorry kids - the dudes from Talibanistan are here. Earmuffs (and eyemuffs I guess...) for now.
UFOs are a metaphor for that. They have basically the same role while preserving the political correctness.
I would like to see more granularity when defining taxes, for instance havin a Tobix tax and similar options, basically anything that is an open debate now in politics, so that you can try both options in the game and see the consequences in this virtual world. Even if they are not completely realistic they can get to be quite pedagogical, IMHO.
That would make this game deep and epic because I do also fear this:
This game is the new spore, it seem deep but its not at all.