DXO released their score for the Nikon D5200. What I found most interesting was that it matched the D7000 for dynamic range, and beat the D7000 at both color depth and high ISO performance. On top of that the D5200 has a higher resolution (24mp vs. 16mp). I don't need the extra resolution for my usual viewing sizes but that extra resolution tends to make noise reduction in postprocessing more effective.
I'm just speculating here but I believe this imbalance (lower-end camera outperforming a higher-end camera) cannot last very long, and therefore it implies that the next high-end DX camera (D7100? D400?) should be coming soon.
Meanwhile the D5200 is an awesome camera. Besides the class-leading sensor and articulating screen, it even includes the smart Auto ISO feature found in the D4, D800 and D600. I would love to have one except that it doesn't have AF fine tuning and a popup commander.