I completely agree that there should be new traits, and a while back I posted some ideas on what they should be.
I like the diplomatic idea that someone mentioned above, but not stealthy. What is a stealthy civ? I can't imagine any particular nation in history being any ore decidedly stealthy than another.
First of all I would change expansionist and commercial slightly (the other civ traits are fine)
Commercial
1) extra gold in city center (as is now)
2) half price commercial buildings (marketplace, bank, stock exchange)
This would make commercial a powerful trait, up there with religious and industrious
Expansionist
1) get rid of scouts; change the explorer unit to be available to expansionist civs only, available from the start, cost 20 shields, move 1, all terrain as roads
2) longer GA, 30 turns instead of 20
Thus expansionists do NOT get better results from goody huts (something I've never really understood), but do have a special unit that can explore the map very quickly, and a longer GA is very powerful.
New ideas:
Artistic (eg Greece, France)
1) non-wonder culture improvements generate 1 extra culture per turn (masterpieces)
2) wonders cost fewer shields to build (80% cost?)
Patriotic
1) one extra citizen born content in each city
2) reduced chance of culture flips (related to number of citizens, say each native citizen reduces culture flip chance by x %)
Civil (can't think of a better name)
1) reduced corruption formula (that commercial now has)
2) half price civil buildings (courthouse, police station, collosseum even)