We’ll certainly do a stream on Paper2D some time in next few months.
In order for workflow to be as seamless as possible (e.g., knowledge of how to work in 3D translates smoothly to 2D, working with same scene components, traces, and queries as you’re used to) and to allow hybrid 2D/3D games, you won’t be able to jettison rest of engine as a whole. However, it should be possible to compile out PhysX and a number of other pieces of middleware to significantly reduce size of runtime binaries. I’ll give that a shot when I get a chance, but I’m aiming for all of Box2D work to be independent, so you can pick 2D physics only, 3D physics only, or both (though individual components will only exist in either 2D physics scene or 3D physics scene).
Cheers,