Apple officially announced that the white iPhone 4 will arrive on April 28th.
Apple today announced that the white iPhone 4 will be available beginning tomorrow. White iPhone 4 models will be available from Apple's online store (www.apple.com), at Apple's retail stores, AT&T and Verizon Wireless stores and select Apple Authorized Resellers.

Internationally, the white iPhone 4 will also be available in Austria, Australia, Belgium, Canada, China, Czech Republic, Denmark, Finland, France, Germany, Hong Kong, Ireland, Italy, Japan, Luxembourg, Macau, Netherlands, New Zealand, Norway, Singapore, South Korea, Spain, Switzerland, Sweden, Taiwan, Thailand, and UK.