Italian iPhone site iPhoneItalia is stating that, according to a "reliable source," the white iPhone 4 will launch in Italy on Tuesday, April 26. Earlier this week Bloomberg confirmed that the white iPhone 4 would be shipping by the end of April. Yesterday, white iPhone 4 part numbers began appearing in Verizon's inventory.
While Apple has yet to confirm an exact launch date, it has confirmed that the white iPhone 4 will be launching this spring. If iPhoneItalia's sources are correct, it's highly likely that Apple has sufficient supplies of the white iPhone 4 to launch in multiple countries, which would mean that the US launch of the white iPhone 4 will also occur on April 26.