My 96-year-old neighbour always has a nice floral display on her property, seems she is growing it just for me. I am a sucker for bright and snappy colors, and Nikon's color palette is ideally suited and biased towards such warmth. I snapped a few files with the "naked" 70-300mm VR and realized I'd be better off with the 500D lens attached. The fly was a bonus.
For macro work, the D80 (or any newer higher-end DSLR) is a MUST since you have a depth of field preview.