The phantom white iPhone 4
When Apple unveiled the iPhone 4 the company showed of both black and white versions. By the time the next generation iPhone shipped, however, only the black models were available along with a promise that white models would be available soon.
So far, the only explanation Apple has offered for the delay is that the white models are “more challenging” to build than anticipated.
Assuming Apple continues with its current iPhone update cycle, new models should be available around June, which means the white iPhone 4 may be available for only a couple months before the next upgrade launch.