Yeah, I agree with Robert. There are only two advantages to DX:
1) Tighter crop factor for shooting telephoto. 2) Smaller, lighter bodies and lenses.
But, number 1 is offset by the fact that it renders formerly nice wide angle lenses useless for their original purpose.
And, number two only applies if you are using amateur lenses. The pro glass is still big and heavy. If you want to travel light, carry a D3200. It takes just as good a photo of stationary subjects in good light.
Other than these two advantages, FX is superior in every way.
But,...the tighter crop is a HUGE advantage to us hobbiests who like to shoot sports, wildlife, and other things at a distance. My AFS 70-300 VR scales to 450mm on DX for shooting field sports ($500). To replicate that on FX, I'd either need a 300 f4 + 1.4 TC ($1,700 and no zoom flexibility, so a deal breaker) or the 80-400 VR ($1,600 and too-slow AF) or the 70-200 f2.8 +2TC ($2,700) or the 400 f2.8 ($9,000, yeah, right!).
Every one of those options is a permanent deal breaker for me, except maybe an updated 80-400 VR (which when replaced will probably be $2,000). This means I would just have to give up sports shooting or limit myself to certain areas of the field, and taking a lot of the fun away. So, I for one, hope that Nikon always makes a decent DX DSLR with at least 5FPS. If they do eliminate this level of DX in the next few years, I might switch to Canon. Even if they eliminate DX bodies as well, their lens lineup is more flexible and affordable for my needs.