Just a few ideas:

1. Overall production workflow, i.e. concept to model/texture to rig/animation to export.

2. Modeling considerations for realtime use: poly counts, detail levels, triangle stripping, object scale, clean transforms, etc.

3. Texturing issues for realtime applications, i.e. mipmapping, texture resolution, normal mapping, etc.

4. Rigging technical details: understanding transform spaces, importance of proper hierarchy setup (generally important but games are super picky about this), Can's and Can't Do's of rigging for games.

5. MEL scripting to aid in general production workflow.