http://en.wikipedia.org/wiki/English_speaking#List_of_Englis...
Yes, there are probably over a hundred other languages still spoken today, but the official and most widely spoken language is English. Almost all (if not all) newspapers are in English, national TV stations are in English, the government communicates exclusively in English, and all elementary schools teach English as a core subject.
Some Nigerians are illiterate, of course, and some never attended school. But the majority of the country, I would say over 90%, speaks some form of English. So it's not just the elite that speak English. Now in rural (and even in urban) areas you will find people that can only communicate in broken English, but broken English is still English.
Like KingOfB, I wonder why "domain.ng" costs $50,000/year!
Edit: Apparently, they're banking on the extension being attractive for things like "im.facebooki.ng". Hmmm.
http://www.loyokezie.com/2011/01/05/at-50000-will-the-ng-cct...