I just pushed a new class, SkeletonAnimator, up to the git repo and updated the unitypackage. 8)
Mecanim is now fully supported by the new SkeletonAnimator (derived from SkeletonRenderer). SkeletonAnimation is still around, but you now have the option of clicking the Generate Mecanim Controller button to create a controller with dummy-animation clips which will keep itself updated with the SkeletonDataAsset when changes are detected.
There's a new context menu if you right click a SkeletonDataAsset in project view under Spine> called Instantiate (Mecanim) - this will handle all of the setup process automagically.
SkeletonUtility and all of its friends are fully compatible with SkeletonAnimator as well.
Events have the same limitation of the native Unity baking process in that they only support 1 data type at a time in the order of preference String, Float (or int), No Arguments.
Also took a pass at Unity 5 compatibility which should be all cleaned up now.
Test the crap out of this please :notme: