They will mine VertCoin and its clones probably (UltraCoin,Execoin). Many people will stick to LTC however just as they did with BTC.
Goldcoin (GLD) is the hidden scrypt gem. There is some sick development going on in Canada with this coin. I believe this is also the developer that invented the 51% defense system.
Additionally, people have always returned to mining Gold. I don't see any reason why suddenly human behavior will change in this Century with digital goldcoin.
So the obvious answer for me is GLD.