Maybe...but I'm NOT 100% sure that Tamron is so bad...of course, owning an a 100% matched/originally Nikkor zoom lens; is better...+ improved VR, but not yet was released, for sure will be released together with the new D-200...so we all soon will be able to read reviews on this lens.
Well... the Tamron isn't that bad a lens, considering the price. It's just that spending a reasonable amount of money on something you don't want is a waste of money. The same goes for spending more money than needed of course.
I do own the 18-200VRII btw.. I just had it for a few days, but I'm still in love with it