Not 100% true. The D90 will handle noise at higher ISO's better, and the increase in resolution helps retain more detail at those higher ISO's.
Yes you're right I though it was the VR but it was the Auto-Focus motor which lack inside my D40... That's also why I was thinking to upgrade to D90. I'd like to have the Sigma 150-500mm but I think it doesn't have the Auto-Focus motor in the lens so with my D40 I'll be stuck with manual focus mode which is kind of a letdown... I do not print my pics however sometime when I crop them I have the feeling that I'm limited with my 6mp. I'd like to see the difference between 6 & 12. Anyway there's always a good excuse to have the greatest and lastest equipment [rofl] Sadly it won't be for now...