>If history is repeated, the D400 (if one is released, and I'm >guessing a direct D300s replacement will be released) will >have an even more advanced AF system than the spectacular >sounding D7000's, a more advanced TTL metering system, a >brighter viewfinder (lower probability on this one), slightly >faster start-up and shutter lag times, better weather sealing, >more AF area mode selections, more cross-type sensors >including more total sensors (Expeed II will take advantage of >them!), and more customization options. > >The price difference will most likely not justify going with >the D400 over the D7000 for anyone but the advanced amateur or >pro who tends to work in inclement weather and has a specific >need for a specific upgraded feature. >
You have me on the AF (although I wouldn't say more advanced, I think it will have more AF points and more cross hair sensors), possible 'better' weather sealing (d7000 has it but it's not clear yet how 'good' it is), and the start-up shutter lag time (but we are going to be talking about a difference of fractions of a millisecond).
I am however of the opinion that the metering system will not change. When Nikon released the D90 they opted to put in the older 420 pixel RGB meter despite having the 1005 pixel meter at their disposal. This was done likely to justify the price range. The meter in the D7000 is brand new and better than anything in any Nikon to date (presuming the increase in pixels actually improves metering). It seems unlikely that Nikon is going to re-re-design the meter over the next year or so.
I think the gap between the D7000 and whatever flagship DX gets released (likely in the next year as sales of the D300s drop like a stone) will be less than the gap between the D90 and D300s. People will still buy the 'high end' DX, but I believe this will be based more on ergonomics than any real advantage in technology.