An alternate view on "trading up"
I agree entirely. I own these cameras: Sony T30 X2; Canon G10; Nikon D3 and a couple of minor items which I will not bother to mention. Between the Nikon and the Canon I think I can cover most demands made of me. I would love to buy a D4. Do I need it? - NO!; Do I want it- Yes!
Sense has a place in my world; if I win the lottery, yes, I would buy one tomorrow, but the D3 and the Canon do all that I NEED!