I also agree that we need more African civs. I am an Egyptian by ancestry (rah, rah Egypt!) and an American citizen by birth, but my mother grew up in Zambia. I therefore propose at there should be an African cultural group with the following civs

by the way govs are assuming that they do not change from civ3)
Zulu (obviously)
Remains the same as in civ3.
Mali
You could run this one or Songhay; it doesn't matter except for leader name. I can't name any Songhay leaders off the top of my head, so I'll use Mali
Mali:
Commercial and Religious
King Mansa Musa
Agression: low
Preferred Gov.: Monarchy (No, duh)
Sunned gov.: This one's tough at first, but then merchants don't exactly like Marx. So the shunned should be Communism
Ethiopia (Abyssinia)
This one was suggested earlier, but I'll add some stuff:
Militaristic and Commercial (please note: most african civs concentrated on trade, so most will have commercial)
Negus Ezama (the one who converted to Christianity and then kicked Nubia's ass)
Agression: high (but not very high)
Preferred gov: Monarchy (again, duh)
Shunned gov: Communism (again, but makes sense considering trade emphasis)
Hausa
I dont know this one that well, but they were the big traders in Central Africa.
Industrious and Commercial
Find your own damn leader
Agression: low
Preferred gov: was collection of city-states, so Feudalism or Republic
Shunned gov.: ummm... see above