Hello,
I jumped knee deep in to see why it was skipping over the import step of the new files I was importing into the new 2d preview build.
The result was that Resources.Load() is not finding the "SpineAssetDatabaseMarker" file.
I confirmed the text file exists and is inside a resources folder inside of my tree.
For the record, the exact path is:
Standard Assets\spine-unity\Editor\Resources\SpineAssetDatabaseMarker
I placed the Spine libraries into Standard Assets in order to improve compile-time performance. (which worked)
Once I moved the file into Resources\SpineAssetDatabaseMarker in my root directory, the importer started working again.
24 Sep 2016, 14:00
tl;dr - user error on my part?