There's been a number of threads. It's mainly campaign stuff - ports, minefields, new historical operations by surface units (Norway, Mediterranean; Bismarck is there too in all its glory), Improved Convoys, and other things that affect the campaign workings.
Keep in mind - this first release is technically just an open first-version beta, which while stable and definitely adds to RUb, is not done by a long shot. You will see improvements to it shortly, first through upcoming Improved Convoys releases (which is part of Ops), and then through subsequent RUb/Ops releases.
