I wrote this out elsewhere:

D5200 Pros:
- Very slightly better low light performance.
- Higher resolution.
- Light weight.
- Articulated display.
- Better video modes.
- Mounts pre-AI lenses (read: very old manual focus).

D7000 Pros:
- More physical control points, including a sub command dial.
- Magnesium body (D5200 is plastic).
- Some weather sealing.
- AF fine tuning.
- Metering with manual focus lenses.
- Optional battery grip.
- Longer battery life.
- Higher speed continuous drive.
- Deeper effective buffer (smaller file size).
- Dual SD card slots.
- Can autofocus with all AF lenses, not just AF-S.

My answer: a D7000 wins, for now. The next generation D7x00 series will I'm sure be still better, but it's not out yet.