Any DSLR will give you good macro shoot, it is the skills of the photographer and the efforts that counts most. Of course a pro/ semi pro DSLR might give you a slightly more edge over an entry level DSLR... but it is not like a miracle machine that when you get one, you will automatically take great macro photo.
Focus more on technique, lighting and a good macro setup, be it styrofoam plate diffuser or ring flash, reverse macro ring or Voigtlander 125mm macro.
Depending on what you have already, a D7k will only likely bring 2-3 advantages to macros:
1. Better dynamic range to recover highlights and shadows.
2. More megapixels so that you can crop more from the existing magnification
3. Lower noise at higher ISO so its less stressful on the flash power/aperture/ISO trade offs when shooting small aperture for macros
Most of the three can already be off set to a degree by better technique/setup.
If you have the budget, D7000 will be a very good choice as a pro-consumer dslr camera in the current market. However as rhino123 said you will also need to have the skills in order to get a good photo.
How much efforts have you spend already reading reviews and understanding the topics you are asking about?
General reviews can be found on the usual review sites, you may start with dpreview.com. For macro you might want to look at macro lenses. There is also an entire subforum here for macro.
Macro is more about the technique and light diffusing rather than the DSLR body. My D80 macro shots are comparable to the D7000 one just that the D7000 allow me to crop a lot more due to the higher resolution.
Most of the time when people asks such questions, they don't need it (gear). They just wish to own it.
Maybe you can try taking more photos and then asking people to critique. I think there are many things to learn and other stuffs/gears to experiment in macro. If they all say you need a D7000 then you probably won't go wrong
read e review.need it buy it..like many have said..its what the camera can offer u (in terms of technical spec) not what pictures it can take..
any camera can take any picture only if you have the skill the technic and not what gears u r using..
i agree with zenix84 "Most of the time when people asks such questions, they don't need it (gear). They just wish to own it."
i usually use to be like this =)