It's not a reimplementation but a gradual publish of existing code, upgraded to meet the required standards (some of it was not written with being open in mind).
WPF will not be available on non-Windows platforms. That has always been the case and will remain so - it has a far to deep integration with the OS for it to ever be platform independent and a reimplementation would be an absolutely ginormous effort.
It's not a reimplementation but a gradual publish of existing code, upgraded to meet the required standards (some of it was not written with being open in mind).
WPF will not be available on non-Windows platforms. That has always been the case and will remain so - it has a far to deep integration with the OS for it to ever be platform independent and a reimplementation would be an absolutely ginormous effort.