“If Scrypt coins go down the same path as Bitcoin has in terms of network security then you can be sure that new altcoins will be developed without SHA-256 and without Scrypt. One such coin that exists today that will actually never have ASICs developed for it is Primecoin. Currently, though there are rumors that some people have figured out GPU mining for Primecoin, Primecoin is still mostly mined on CPUs. The different hashing algorithm in Primecoin makes it the first altcoin that does “useful” proof-of-work. Since Primecoin’s debut just four months ago already 3 new primes have been discovered. In the coming world where regulation may justify the existence of altcoins by necessitating their use in crypto-only exchanges that exist explicitly outside of the law, Primecoin is king because it will maintain the original decentralized mining network that Satoshi envisioned.”
http://www.cryptocoinsnews.com/2013/11/22/alpha-technologies-offer-scrypt-mining-asics/