Previously when I tested the Zevo prefpane with Mavericks, the OS refused to load it and it wouldn't even show up in System Preferences. Today I turned on one of my Mavericks development machines, updated to the most recent version of Mavericks, and amazingly Zevo shows up in System Preferences. I won't have my ZFS disks handy to test it for a few hours but it's an encouraging sign.