Ah, ok. 🙂
There will be a new class, MeshAttachment. This is similar to a RegionAttachment, but has a texture region, vertices, UVs, and triangles instead of a texture region, SRT, width, and height. The triangles are exported so runtimes don't need to worry about triangulation. The MeshAttachment is given a bone and computes world positions for the vertices. FFD is done by an animation timeline adjusting MeshAttachment vertices.
There will be another class, called something like SkinMeshAttachment. This extends (or is similar to) MeshAttachment and has a list of bones and weights per vertex. Instead of computing world vertices for a single bone, it does it for each bone and then uses a weighted average as the actual world vertices.
IK pinning doesn't affect the runtimes. It is the furthest away of the new features. At the very least it will be used to keep a bone tip in place for posing, like the opposite of the Pose tool. At most it will plot the IK movement during export, writing out the plotted keys.
