ether and zcash live on separate chains. there's work underway that could allow for trustless cross chain exchange between ether and zcash (https://z.cash/blog/

ether and zcash live on separate chains. there's work underway that could allow for trustless cross chain exchange between ether and zcash (https://z.cash/blog/project-alchemy.html https://z.cash/blog/project-alchemy.html). This new crypto primitive in Byzantium is one of the things required for that project. with Byzantium, it's now possible to create a zcash-like token on top of ethereum (it would however be wholly separate from zcash). since it lives inside of ethereum, it would be easy to exchange for ether. however, its value would float separately. it might look something like this: https://github.com/zcash-hackworks/babyzoe https://github.com/zcash-hackworks/babyzoe. Byzantium also makes it possible to create an ethereum contract into which you can deposit ether (locking it up), transact around privately with others, and then later withdraw back out into ether.