ThisDay (Tanzania), Tanzanians go to church, the mosque and the witch doctor, 21 Apr 2010, "As sub-Saharan Africa looks to the future, an intriguing attachment remains to the traditional beliefs that many Christian and Muslim leaders condemn.
"Though it may be that influences from beyond Africa, not least those available through the power of the internet, may yet contribute most to changes in the religious landscape in future."
This is an informative article. Take a look at the Pew Forum survey, Tolerance and Tension: Islam and Christianity in Sub-Saharan Africa, April 15, 2010. The full report is available as a pdf - which should make for fascinating reading