All Nikon DSLRs will be full frame.
DX sensor will move to point and shoots - ie Coolpix.
But it'll be 18 months before we see a D90 class body with a full frame sensor I reckon.
3 years ago, I had quite a fierce debate with someone about the emergence of full frame, the basics were that
Me - My argument is that SLR started with 35mm, and crop is a phase and eventually all DSLR will return to FF.
The other person - He said that Nikon will
NEVER produce a Full Frame DSLR as they have invested too much into their DX lenses to let them slide.
I also said that at the time (20D just came out), that the 30D will be Full Frame (wrong), and that I won't get a full frame camera until it hit around £1k (wrong again, I got a 5Dii now).
Thing is, I think the market has settled to a point where APS-C sensor is here to stay.
Full Frame - will always have a price premium, £2k+
APS-C - for the lower end of the market.
Reason is money, you can't get around it, Full Frame sensor costs more to produce, even if the yield success rate has gone up and the production costs has gone down, so would the cost of producing a APS-C sensor would also have come down. People are still buying APS-C sensors by the bucket loads, along with the EF-S and DX lenses.
No doubt a £1k Full Frame camera will sweep the market by storm, thing is, there already is one, the 5D. People tend to forget that, just because it's old, towards the end of it's cycle, it was retailing for £1,000. As for a new model coming out at £1,000, sure, eventually there WILL be one, but i doubt it'll be for a while. When it will be, you bet that it's AF + other features won't be as good as bigger brothers.