To the TS,
If you do a search here you will find many threads on the rumoured D400. quite tiring to see all these rumours.
We are not a Nikon rumour site where our main preoccupation is rumour mongering. Let's focus on getting good images from our camera and improving our skill.
Having said that we still can and will like to know if the product has reached it shelf life or any new models coming out. So that we do not end in a situation of buying a D300 when within a few days or 1 week a new model comes out replacing it. Which some members are caught off guard with the launch of the D5000.
Nobody here is none the wiser and certainly the decision is yours to make, taking into considerations of the views in the Nikon rumour sites, dpreview etc etc and of course CS. To say the D400 will be coming out is as good as say the sun will rise form the east, cos D400 will come but when?
The D300 is out only about 1.5yr, together with the D3. It was out the world and revolutionary then and is still one of the best. It still have plenty to offer and quite some useful years to go in the hands of a good photog.
My guess is if you can wait for at least half a year or slightly longer, you may see the D400.
Nikon had regain the market for the higher end DSLR from D300 to D3, esp the D700 last year. I would think this year the concentration is to gain a bigger market share is in the the lower and more affordable DSLR market. Hence the D5000 and also the DX lenses not forgetting the other FX lenses.
Times are bad and ppl are not willing to spend too much for higher end cam, (including the pros), some of the some retailers told me that D3X is moving very slow.
I may be wrong
My apologies if you are offended by my earlier reply. I hope the rest of the members give the TS a break too
PS: D750, I can safely say it is rubbish at this moment.