Categorifying von Neumann algebras, 2

We'll continue last week's discussion of categorifying von Neumann algebras. Even though last week was mostly spent on a crash course on von Neumann algebra's, likely the discussion this week will be essentially independent. We'll need to discuss the categorified notions of centers and commutants, and then think about which properties of the 2-category of bimodules between a pair of rings should be lifted to a putative 3-category of bimodule categories between a pair of tensor categories.