I'm still on the original iPhone since day 1 of release so this is killing me to wait further. However, with all the problems of the iPhone 4, and the free bumper/case offer only lasting until Sept 30th, I wonder if they wont release the White version with some minor internal updates to fix the issues around that time.
Especially given Jan 2011 is the rumor for Verizon to get the iPhone, they may have an iPhone 4+ version they rush to market. Technology adoption is always a gamble when to buy as something newer is always around the corner. So for now, I will wait...