"Have you given up on a D400 and bought something else?"
I have not given up on the D400, but that is not why I have not bought something else. At this point I'm still trying to decide if I really need to upgrade the body. Once I decide, I will buy whichever body fits my needs (wants?) better. If I were to buy today, it would probably be the D7100. If a DX D400 is introduced before I make my decision, it would likely have a feature set that I would prefer, and I would likely buy the D400. If, as some have speculated, the mythical D400 turns out to be FX, then I would likely pass on it. I know FX has advantages, but not enough for me to spend the extra cash.