That keyboard shortcut do exist in PPro 1.x and was for some stange reason taken away in PPro 2.0. Big mistake imo.
I used Workspaces in PPro 1.x to easily/fast switch focus between windows sometimes, but in PPro 2.0 this dont work so well. If i in PPro 1.x saved a workspace with my Timeline active the Timeline always became that active window when i launched that Workspace. In PPro 2.0 that trick works one out of ten times wich makes it worthless. Maybe Adobe borrowed some Random Seed from AE for the Workspaces in PPro 2.0… 😉
I sure hope Adobe gets this shortcut and the other ones they forgot in PPro 2.0 back into PPro 2.5 again. 🙂
/Roger