The D5100 would have been a pointless upgrade since I had a D5000. On paper it's a D5000 with better video (which I don't use) and higher MP count yet exactly the same ISO range as the D5000... which seemed pointless.
The D7000 has a lot more than the D5100. The D7000 replaces Nikon's flagship consumer DSLR the D90. The D7000 features more focus points, wider ISO range, better ISO performance, more metering and white balance settings, mirror lock up, weather sealing, auto focus compatible with all previous Nikon lenses (thanks to having the focus motor in the camera body not the lenses like the lower DX models), dual card slots, 6fps shooting, auto focus video recording, speedlight commander modes, higher maximum shutter speed and much more.
The D7000 is quite a bit more expensive than the D5100, this doesn't mean the D5100 is bad just that the D7000 features quite a bit more. You do though have to ask yourself if you need all these features. For me the winners were ISO performance and in body focus motor.
The D7000 and 60D are basically equivalent cameras, with each having their pros and cons over the other. If you are aiming that high then fair enough, although it may be a bit excessive for your needs you'll still get a great camera.