Just purchased a Nikon D100 (still waiting for the delivery) after going through some intense research and head scratching. What made up my mind was the Nikkor lenses I already have. If I were starting from scratch, I probably would have gone with the Canon 10D. (Slightly more resolution (6.3 MP vs. 6.1), cleaner images (less noise), ISO starting at 100 (D100 starts at 200)). That being said, these "differences" are minimal - not worth dumping my existing lenses. A good way to decide is to define what type of photography you want to do, and go with the system that offers an equipment line that fits the definition. Both Canon and Nikon have virtually everything you could possibly want (Nikon may have the edge, since they haven't changed the lens mount since the old Nikkormat series) Nikon's "new" DSLR is the D70 - a slight drop from the D100 designed to compete with the Canon Digital Rebel, and will be priced below a grand.