Science has an authoritative estimate of deaths in Darfur. It's between 170 and 250, 000. (via the BBC)
Tomorrow, September 17th, is the international day for darfur. Please consider getting involved; you might want to read up on things here, here, and here. Check out Daniel Davies' slightly contrarian take on things here and here. And these two articles by Alex de Waal are lucid and informative, if a little old.