I think the more coins the better (at least more non direct clones of other coins.) because as people modify and adapt new coins they bring new ideas to the table. In the end they all help out by proving or disproving difrent aspects of the whole virtiual/crypto curency trade and manufacturing.

Bitcoin and Litecoin are at the moment the only coins that have got anywhere (my opinion ofcause) and they arnt without thire flaws. The more coins we have the more chance  the holes get pluged in what ever becomes the next Bitcoin.