Maybe I should say when I see a large premine, my initial thoughts are it is a scamcoin.
A large premine is an indicator of a scam coin, but doesn't automatically make it one.


"Litecoin had two blocks premined, one more than the minimum single genesis block needed to start a block chain."
Source: https://en.bitcoin.it/wiki/Litecoin#.28Slight.29_Premining

If the statement above is true, then all coins would need to be premined.