I would definitely like to see more information about the Object Manager and how the subsystems work (e.g. how a process chooses a subsystem and what implications that has on the interfaces available to it). Also, maybe some discussion on the future of subsystems (ok, Win32 "won" -- does that mean the concept of multiple subsystems is somewhat obsolete and from now on we'll all build on top of Win32, or does it make sense to have, say, a .NET subsystem if .NET is really going to supercede Win32?).