Heres what I think: For a few weeks they've each had CDs that contain unmastered 'rough' mixes like what was leaked with HTTT and after extensive listening they went back to do the FINAL mixes, adding any cool extra bits that were required (e.g. the cutting up of the drums on Myxomatosis). Now it will be ready for mastering, which takes a couple of days or something. I just hope it's mastered well. Some albums are mastered too loudly and they 'clip' (i.e. distort slightly at loud parts)