Pamela:
A digital SLR with over 10mp - I think you will be thrilled. Especially with it's low light capabilities compared to your 5700. Here is a side by side comparison with it's predecessor the D100. The D100 was (and still is, hay Garth) a terrific camera and yet the D200 surpasses it in every category.
http://www.dpreview.com/reviews/nikond200/
I don't have any direct experience with this new camera. I will be pointing my D70 for many years to come.