I made my thoughts in a list so everyone can add, remove, and discuss. I would really like to see the motion tracking calibrated stuff make it to reality. I also haven't seen anyone with the idea to have real sex with oculus.
Adult Game Features:

General Adult 3d game features.
Extremely customizable in depth avatars/models.
High to low scale models. eg 3d action figure size to giant
Customizable environments.
Easy to share avatars/models skin system.
Voice recognition interactive model AI. eg "Turn around."
Ability to record.
multiplayer.

Motion tracking Features:

Compatible with all motion tracking hardware available. eg PrioVR Stem Hdra
Calibrate any hardware with any model skeleton. eg low scale model for some adult toys, or scale to lifesize.
Calibrate hardware with modeled objects. eg hdra to dildo
Calibrate hardware with environment. eg real bed, couch, desk
Calibrate hardware with 2 player. eg sex with real partner PrioVR/Stem
Calibrated online multiplayer

So you can take something like prio or hdra, and "tie" them onto sex toys. Calibration and combination with slow to high scale model skeletons would be great for small dolls, blow up/plush, strokers, dildos, and realistic adult toys.