I think the idea, while interesting on the surface, lacks two critical things:
A) Coin legitimacy. As we've seen from all the CrapCoins, it's fairly difficult to get a coin to the point of critical mass where people want it such that it has value.
B) A balancing mechanism. Miners will mine whatever is most profitable. Today, that means Bitcoin. If all the miners chase whatever is the most profitable at the time, you will see all that hashpower constantly chasing whichever coin is hot at the moment. You can see this effect at multipool.us, as their entire pool is switched based on the relative exchange rates between Bitcoin and the various altcoins. Lacking any kind of formal balancing mechanism, that phenomenon will continue to exist.
You are absolutely correct that creating "Legitimacy" of a new coin is very difficult. That is why i posted this thread here, to hopefully make a community effort.
No balancing mechanism will be necessary if the coin chains are legit on par with bitcoin. In other words they speculatory value of coins will be tracki9ng with bitcoin and other 4 chains, so all chains are just about equally profitable all the time.
One possibility would be to mimic the datacoin chain. Yes i know datacoin is not sha-256. How about making a cousin of datacoin, with 2 differences:
1. the chain is sha-256
2. The data stored in the block chain can be altered by original contributor. This means the block chain can be used as means of unregulated mass communication.