v0.7 is good to go. Executables for all four supported targets (Windows 32-/64-bit, Linux/amd64, Mac 64-bit) have been uploaded yesterday. Upgrade from v0.6.6.2 isn't required at this moment, though advised strongly.

Note that github.com/ghostlander/Phoenixcoin refers to the v0.7 repository now. The previous repository has been renamed to Phoenixcoin-v0.6 there.