I think that it is a very accurate assertion to suggest that the battle in Mali could become the French equivalent of the war in Afghanistan. Both areas involve militant muslims and a history of violence, not to mention a very rough geographic area. Only time will be able to tell.
Mali is a huge unwieldy country and it is very possible that it could turn into an Afghanistan-like situation for France. The problem is that there is no standing army to go after, which makes combat tricky and deadly. The French army will be going after rebels groups who can pop up here and there. It sounds very much like Afghanistan.
Mali will most likely not become an Afghanistan-like ordeal for the French. The government of Mali asked France to intervene. This is a big difference between the Mali military campaign and how the United States started a war with Afghanistan. France has also asked many other countries to get involved and doesn't plan on staying there after the rebels are disabled.
While there is a risk of Mali becoming France's Afghanistan, it might go a very different way. France has been to war in Africa before in the last couple of decades. They were successful in their interventions and were able to get out of Africa before they became embroiled in civil wars and extended military campaigns.