What are you using right now? The D5200 and D7000 are entirely different beasts. Yes, they share the same AF system, and the D5200 has more pixels, but the D7000 has all of its key controls at your fingertips, has a more robust body, dual card slots, takes AF lenses, can control external flashes via CLS from the on-board flash and has a battery grip available for it.
I was intrigued by the option of 24MP, but after handling a D5200, I decided to pass on buying one and stick with both of my D7000s.
The D7000 is just over two years old which is long in the tooth by current measures, but it is and will remain one hell of a camera for several years to come.