Nigeria's political coming-of-age moment

I have to say that, probably like many others, I am surprised, nay, shocked that Nigeria's elections have concluded apparently without bloodshed. Call me cynical, but what were the odds against that?
I imagine most betting people were expecting outgoing president Goodluck Jonathan to throw a tantrum, allege massive voting irregularities, and launch an all-out civil war/coup d'état. In fact, the election seems to have been remarkably free from the usual vote-rigging, manipulation and intimidation, despite being so closely fought.
I'm not totally convinced that Muhammadu Buhari - a 72-year old Muslim ex-general and oil minister during the military dictatorship of the 1970s - is the best thing that has ever happened to the country. But, given that this is the first time in Nigeria's supposedly democratic era (since 1999) that a leader has actually accepted democratic defeat, I think we should probably be grateful for small mercies. This may even be Nigeria's political coming-of-age moment.
Nigeria is the most populous and also the wealthiest country in Africa, and ranks 30th in the world in terms of GDP, although these statistics hide some huge discrepancies in income. It is the tenth largest oil producer in the world, and 70% of its government revenue comes from oil. But it has always been somewhat benighted politically, and regularly appears towards the bottom of the international corruption listings. The country also has the complication of being composed of around 250 different ethnic groups (Charles de Gaulle once complained "How can you govern a country which has two hundred and forty-six varieties of cheese?", but imagine governing that many different ethic groups).
A quick perusal of a map of the voting by states shows an almost complete geographical split, with Buhari claiming the mainly Muslim, Hausa-speaking and less-developed north (which is also where most of the Boko Haram terrorist activity has taken place), and Jonathan taking the more developed Christian south. That in itself sounds like a recipe for disaster. But Buhari was voted in on a pledge to fight corruption and to "deal with" Boko Haram, so let's give him the benefit of the doubt, and give credit to Goodluck Jonathan for stepping down with some grace.