And the golden rule remains - only leave your funds on an exchange for the minimum time - trade and get out.
There is just a small alarm bell related to the vulnerability of central control by a malicious dev or other group - for any coin.

The first point is a great piece of advice, so many people get lazy and just leave coins on exchanges, until someone creates a truly decentralised exchange, buyer beware *cough*Gox*cough*
Well, I'm glad I always followed this rule. Until now, there were three exchanges (Mt.Gox, MintPal and another one I used to trade on) which ran into problems and in at least two of those cases I would have lost a considerable amount of money if I had left my coins at the exchange.
So please, guys. Follow this advice!