ASIC's are an unstoppable part of any cryptographic 'coin' as it gets more accepted and widespread. It would seem that at the moment Litecoin is 'safe' from ASIC's and can only be mined by GPU's, but an ASIC is sure to come if Litecoin gains fame and widespread acceptance like Bitcoin does.
Not really. The hashing algorithm Bitcoin uses was designed for efficient ASIC implementation, whereas litecoin uses scrypt which is structured to reduce the advantage an ASIC has over general-purpose hardware.