Zerocoin is pretty complicated comparing to the Bitcoin alternatives: CoinJoin, CoinSwap and CoinControl which offer practically the same functionality.
I don't think we need ZeroCoin anymore.
Zerocoin being released as an alt-coin is surprisingly needed, but it is okay if you don't notice that.
Why is it needed, you ask ? Well, because except for Litecoin, 99.999999% of all the other alt-coins are just crappy-coins from people that can manage to search-copy-replace text. Litecoin is only valuable to bitcoin because the main developer there can manage to contribute back.
Why, again, is it needed, you ask ? Well, start following some of the key developers for bitcoin and you will quickly realize that their line of thought are no longer aligned with the original proposal, or even with the idea of open source software.