What happened to zerocoin?
Well it's implemented in the code but Zerocoin has abandoned that for a new Zerocash (coin) that they will announce or atleast press release something about on tuesday. So Liberty is going to look at other things like darksend and the coinmixer coinjoin as well as the Zerocash thing. Darksend has the best name recognition and is actually a wallet thing rather than coin for Darkcoin. IMHO having the coin anonymous and the wallet mixer/ anonymouzer would be the best situation.