Well, Cheech and Chong might be behind this rumour, but the iPhone 4 is finally launching in white on April 20th (420). This is what appears to be happening at the UK carrier 3.
The iPhone can be seen on their site
It will come in 16gb and 32gb configurations.
It looks like the iPhone 4, after all its delays, will actually be launching. And with the iPhone 5 possibly delayed until September, it might be worth picking up one of these guys.