I suppose I'd have two questions about this.

One is what proportion of ordinary people could actually get access to bitcoins in third world nations.

Another is whether bitcoin mining will wind-up being a way to launder money and access to energy in the third world - we often hear about oil, diamonds and minerals being taken during conflicts in third world nations. If someone could turn oil into wealth with nothing more than an Internet connection and a portable server-farm, a whole range of abuses might be possible. It's been claim bitcoin mining in China can be a way to subvert currency controls already.