I make the claim that Capitalism is on the right track to go extinct because I believe that the transparency that exists in today's culture has set us Capitalism to one day be replaced. There is a lot more scrutiny of the action of Government officials due to the miracle that is The Internet. Government fatcats and Corporate fatcats can't freely make deals and there are watchdog groups all over. Maybe it's wishful thinking but I think Capitalism as a way of life in America is on the way down and out.
First, capitalism isn't quite a form of government, per se, but rather a economic system. Regardless, it will never go away because the root of capitalism is private ownership of the means of production. And history has shown that with private ownership, resources are allocated in the most social efficient ways possible. Such is the natural order of capital and wealth.
Capitalism being injected into socialist China and several other socialist countries is the reason why they are expanding. I'm not saying unfettered capitalism is a good idea either, because it's not. But forms of government need to be combined for mixed economies. They have to compliment and temper one another.
Capitalism as it is traditionally known is certainly not going to stick around like it always has. The world is moving too fast and changing too much for capitalism to remain as is. Still, there are not really any fully viable alternatives. So while capitalism does have to learn how to co-exist with socialism and managed economies, it is not going anywhere either.