Since this is a community project being developed by individuals donating their free time and skills for such an undertaking, progress will be slow. Projects like this can take several years to complete and may eventually be cancelled due to lack volunteers or life changing events which impacts the amount of time people can devote to such a project.
From what I understand, the developers have raised enough money to license the Unity Pro game engine back in Sept 2011. When will it be released? Unknown; as stated above, a project like this can take several years.