I agree with fragilesi. I think the market will determine the value based on the demand for the particular features of the 7DII. I also think it is that market differentiation that will drive the features of the 7DII.
That's why I would not be at all surprised to see the 7DII as a 24mp, high frames per second, weathersealed, state-of-the-art autofocusing up to f8, camera that will have birders and sports shooters lining up to buy it. It's also why I expect that that it will not be a great low-light, high ISO performer – that's what full frame is for.
However, I strongly doubt it will 24MP, and I highly suspect that it will have the same sensor as the 70D.
Even so, let me add a feature not frequently discussed - if it is a true successor to the 7D and/or a little brother to the 1DX, then it will have dual Digic processors, may be even 3 (at this point, I don't know which Digics yet). But, what exactly needs that much power if it isn't feature rich and/or better than the 70D? Or even the 6D, as some of you dispute?