Comments about Nikon Nikon D5100 DX-Format Digital SLR Camera Kit with 18mm - 55mm f/3.5-5.6G AF-S DX (VR) Lens:

AS a prior D90 shooter, I can say without reservation that the D5100 is now Nikon's biggest bang for your buck/Pound/Euro/Yen, etc. The AF accuracy on this camera is much better than what I experienced with the D90. Image quality is astoundingly superior (i.e, great noise reduction while image stays sharp, sharp, sharp).
Contrary to what has been written by others (e.g., Ken Rockwell), I find the "i" (Information menu) option for setting changes (e.g., ISO) to be quite fast and easy, once you "get" how to use it (in lieu of hunting for buttons or dials or button/dial combinations for everything). And, most importantly, the Command dial is still where it should be for quickly changing exposure settings.
In agreement with Rockwell, if you want a heavier DX camera and want to pay $400(US) more for all those buttons, be my guest and buy the D7000 instead. Perhaps you need a larger viewfinder, or have older and/or AF-D lenses that need a built-in (camera) AF motor to focus. If so, then spending the additional money for the D7000 might be worth it. (Or maybe you just enjoy the technology at least as much as the art. That's cool, to each their own.)
If you stay in Nikon's line-up, only a heavier/more expensive FX D700 can produce better IQ (and I would say perhaps, depending on conditions, because the resolution of the D5100 with 16+MP is really phenomenal).
With this steal of a camera, I've put together the following steal of a kit: D5100 camera with--Tamron 10-24mm f/3.5-4.5 DI-II B.I.M., Sigma 17-70mm f/2.8-4 OS HSM (killer fast walkaround, stays on the camera), Nikon 35 F/1.8 (only prime - honestly not used much), Nikon 70-300mm. For under $2500 US, I have everything I need or want.

Do yourself a huge favor and trade up to the Nikon D5100 now, from whatever you have, before they run out.