Statement by Apple on White iPhone 4
White models of Apple’s new iPhone® 4 have continued to be more challenging to manufacture than we originally expected, and as a result they will not be available until later this year. The availability of the more popular iPhone 4 black models is not affected.
"not be available until later this year"だそうです。白待ちの人は厳しい決断を迫られそうですね。