Many Catholics no longer attend church for many reasons. The ideologies and needs of the flock have changed. A black Pope could come to the Papacy with new and inventive ideas. I believe a black Pope could unite an otherwise waning congregation. He could bring a new and invigorating message.
No Pope has ever been black (at least that we know of). So the odds are against the next pope being black. Of course that is all just background information. If we apply Bayes theorem, and there happen to be specific reasons to think the next Pope might be black (e.g. talk amongst cardinals of electing a black pope), then it could be new evidence is enough to overcome the prior probability from our background information. But I don't know of any such evidence. All I have to go on are the priors, and the priors say no.
It might happen if pigs grow wings and fly. Only 3 million or 3% of Catholics in America are black. Only 16 of the 434 bishops in the USA are black. There are about 200 million black catholics, mainly in Africa. There are 183 cardinals in the Catholic Church worldwide. Only 117 cardinals are eligible to vote for the new Pope. 11 are from Africa
The bookmakers have the new pope coming from Italy, a 6-5 favorite
Racial issues in the papacy are simply not as important as the triumph of secularism in the post-Christian Western world. That said, I do not believe the new pope will be black because most of the candidates are white. As philochristos said, it's statistically improbable. However, when looking for a new pope, the Church should be more concerned with the secular machine advancing on religion rather than the race of our leader.