I'd like to point out one thing I think you missed there, and that thing is the one definite amongst a whole lot of maybe. The first codex of 6th edition will be Codex: Space Marines.
They always get the first codex after a new edition, it happened with 4th, it happened with 5th, and it will happen with 6th, 7th, 8th ect.
I don't see SMs being directly followed by CSMs, I think GW will put something else between them, maybe Tau or Eldar. Although I suppose there are a number of power armoured releases which are incoming, BTs and maybe DAs in addition to SMs and Chaos so you never know.