I think the D400 will use the same sensor and meter as the D7000 along with a similar AF unit (modified). I don't see image quality, DR or ISO performance changing. Whatever distance there is between a D7000 and a D3(s)/(x) right now is probably not going to change substantially. Right now the D7000 seems to be giving affordable fx (the D700) a real run, and it is not that far off from the 'big boys' in the fx range that most users can't afford or justify anyway. That will continue with the D400.