Now that the first-gen iPhone has launched or is launching all over Europe, the rumors about the 2nd-gen 3G iPhone are already starting.

The crux of this rumor comes from Spain where the country would have liked to launch the iPhone in time for the holiday season this year, but Apple has supposedly been unable to meet handset production demand and so the date will have to be pushed. One of the reasons Apple supposedly can’t meet demand? The Register article suggests it could be because they are hard at work on the 3G iPhone that they want to get out the door by May 2008.

Quite frankly I’m not sure how believable this rumor is since that will put the 3G iPhone within only about 6 months of the 1st-gen iPhone in much of Europe where having a 3G version is arguably more important than it was in the United States. Of course maybe they mean for the May 2008 date to be a U.S. roll out with a European one coming later in the year, but I would guess neither continent will see a 3G iPhone until late next year at the earliest.