The announcemet of this new Nikon offering has caught me by surprise. I should have paid more attention to the rumours. Just a few weeks ago I bought a D3200 with the hope that the extra resolution of 24mp would at least partially compensate for the less-than-excellent performance of the Tamron 70-300 VC when fully extended.
I've been pleasantly surprised that the combination of zoom-quality 300mm lens plus
24mp-quality cropped-format sensor, produces results which are approximately on a par with my Canon 50D with 100-400 zoom used at 400mm.
When I bought the D3200, I was aware of it's limitations as an entry level camera, such as 12 bit processing and no auto-exposure bracketing. However, at a cost of just $400 I felt I couldn't go far wrong. If the camera wasn't suitable for my purposes, I would give it away as a present or sell it to a neighbour.
What I'd forgotten to take into consideration was the fact that the D3200 does not have any AF Fine Tuning feature. When I attempted to compare my Nikkor 24-120/F4 with the Tamron 70-300 VC, at focal lengths that both lenses have in common, I was initially surprised to see that the Tamron appeared to be significantly sharper in the centre of the image where I'd focussed, then quickly realised that the Nikkor lens was back-focussing with this new body. Without AF Fine Tuning, there's nothing I can do about this, except use LiveView and tripod.
For this reason alone I might be prepared to buy the D7100, but when I considered all the other advantages compared with the D3200, such as 14 bit processing, a huge range of auto-exposure bracketing options of up to 5 exposures with an interval ranging from 1/3rd to 3EV, no AA filter for that slightly greater crispness of detail, faster frame rate, much better autofocussing, and a water-sealed body, then the decision was easy. I placed a pre-order immediately. I expect to receive the camera by the end of March.
Wow! Things are sure getting interesting in the Nikon world.