Even before the new codex the fluff had begun to change:
This was most definitely a book about NEWcrons, and it was awesome. I was expecting the same old boring robots but what I got was personality, strife, politics, and betrayal.
The only thing I dislike about the new fluff is the c'tan nerf. I agree it was stupid to have a freaking Star God on the table, but I think they could've worked out a better solution.