It is healthy. It's called the free market combined with open source software. The coins are like organisms in a rapidly evolving natural selection process. Only the fittest will survive, and these coins will have the best properties for an online currency.
Everyone knows crypto currency will be the mainstream. The process by which we get there; however, may surprise you.
I personally like this natural selection process. And, while the new ideas are brewing and evolving, it's only natural people will tinker and invest.
Cryptocurrency becoming a mainstream success is NOT a given - we're talking about overthrowing the banking and financial system that is more powerful than any entity on this planet.
Normally I wouldn't mind what goes on here, but short-sighted and frankly moronic exchanges like Mtgox are lusting over the money that degenerate gamblers will bring into their system so don't mind hurting the overall credibility of Bitcoin by introducing some copy coins into their system - at a time when people are barely struggling to understand what Bitcoin is.
It's not as if these altcoins are providing any new legit innovation into the system - they are almost all get-rich-quick clones that serve no real purpose other than making a quick buck off the name of Bitcoin and the success that it's had.