I think the Nikon executive Richard quoted was pretty much spot on.
There are excellent cameras from all manufacturers and within any particular range of cameras the differences are often fairly marginal.
James, I can comment on only one of the two DSLRs you are considering - the K5. There may be some photographers that have used both it and the D7000 but I think there will not be many.
However, my final choice when buying my DSLR was between the K5 and the D7000. I decided to buy the K5 because of a certain amount of long standing liking for Pentax (I still own a 35mm film Pentax SLR I bought in the mid 1970s), the few old K mount lenses I own which I knew would (with some limitations) work with the K5 and the in camera image stabilisation (in the future I don't have to buy IS lenses and all the old lenses are stabilised).
I did read the reviews but the differences were not great enough to swing me towards either camera.
If you like the K5 and particularly if you have any good old K mount lenses it would be good buy, but you will get an equally good camera if you buy the D7000 and a much larger dealership. Try to handle both to see how each feels to you. Either way you are going to get a good camera.
Don't know your location but in the UK the D7000 is about 20% more expensive than the K5
Dave