CNNMoney.com's Apple 2.0 article is describing how the iPhone 3g 8gig is disappearing like the 2g phone originally did.

There are only a handful of stores across the nation that still have the 8g in stock anymore. About 36 of Apple’s 197 stores to be a little more precise. If it is any hint at what happened previously then it might mean that a rumored 32g iPhone is on its way but it is a little soon to be sure.

However it might just be possible that Apple didn’t expect to run out of the iPhones so soon so they are simply out of stock. But that would be an unusual move for Apple. So if you wanna get an 8g iPhone you better hurry to your local Apple store!