Sources are reporting that UK's O2 has posted this notice on their website saying that both of Apple's currently available iPhone models, the 8GB iPhone and the 16GB iPhone, are no longer available in the respective territory. Either the iPhone is selling like water in the desert over there, or Apple is planning an earlier release of the 3G model.

The latter option is less likely to be the case. Actually, the former scenario is a bit far-fetched as well, because Apple would certainly make sure O2 UK is getting all the iPhones it can sell. So what's going on? No one knows. Engadget came up with the news that O2 had posted a notice saying it had no more 8GB and 16GB iPhones in stock, as far as UK was concerned, and that's pretty much it. No reason for it whatsoever is even hinted at.

However, this does confirm earlier reports that O2 was planning to kill the 8GB iPhone. They didn't say anything about the 16 giger though, and quite frankly it doesn't even make much sense to stop selling the better model of a device just three months after its release.

Everyone (including analysts) is saying that Apple will most likely launch the next-gen version of its handset at the World Wide Developers Conference (WWDC) in June this year. No reason to believe Apple has changed its mind, so it's everyone's guess why O2 UK emptied its stock and "forgot" to refill it with handsets.

For the first time in the event's history, Apple's 2008 WWDC will feature sessions for developers building native applications for the iPhone using the SDK. "Get Started," "Build Powerful Applications," "Integrate the Technologies of iPhone" and "Create Engaging Media Experiences" are just some of the featured sessions at WWDC 2008, which takes place on June 9-13, at the Moscone Center in San Francisco.

Also, Apple's CEO, Steve Jobs, will introduce firmware 2.0 for iPhone/iPod touchat at this year's WWDC.