which is really my point. There is no question the D3 is a much better camera than the D300 and the 200-400 is in a different league (and 15x cost!) to the 70-300 but in that situation at least the D300 held its own. Which was my experience when I tried the D7000. Yes the IQ was better but in most situations it just wasn't enough of a difference to make it worth moving away from the 300.
The D300 is a fantastic camera. The D7000 is an improvement over it in many ways, but as with most steps forward in camera development, the differences between one step and another aren't significant enough to warrant upgrading, usually it's the next but one step where it starts to make sense.
The D7000 is anomaly. Clearly, it's the new D90, and yet the D90 is still a current model. The improvement in sensor, high ISO performance, metering and addition of HD video mean that the D7000 is going to be cannibalising sales from the D300s.
My gut feeling is that the sensor in the D7000 was also destined to be in the D300s replacement, but a combination of the Tsunami, economic downturn/recession, success of the D7000 and the need for Nikon to launch a compact camera system has meant that the D300s replacement has been pushed back.
As such, we're in a similar position to when Nikon launched the D70, which in many ways was a better camera than the D100 but a fraction of the cost.
