Pictures say a thousand words. Its the man behind the camera who will bring out the true beauty of each picture he takes, the camera will only enahnce the picture quality (in a sense). Be it D70 or 350D, it the composition of the photograph that counts.
How you start your photography hobby will also be another determining factor. If you started off with the Nikon system, I would think you will continue to use their digital camera since you have built up your collection of lenses.
Just my thought!