Is the import/export of GLTF files is going to be supported or is there a python script that can handle that?
There is an exporter available here: https://github.com/Kupoman/blendergltf
While its work-in-progress, its already usable for exporting textured meshes.
It looks like the Khronos Group also has an official exporter for version 2.0: https://github.com/KhronosGroup/glTF-Blender-Exporter
Blender 2.80+ now ships with glTF-Blender-IO pre-installed. This is a combination of the original Khronos glTF exporter with Julien Duroure's glTF importer.
The Blender Manual has documentation on importing and exporting glTF, including a section on how to get physically-based (PBR) materials to glTF.
There is also seems to be alpha version of importer: https://github.com/ksons/gltf-blender-importer
Verge3D comes with a well-maintained and open-source Blender to glTF (GLB) exporter. Check it out on GitHub.