Which is a bit of a conundrum. If the new iPhone were to be released in June, you'd expect there to be more noise on the channel by now. But if it's coming in October, it's far too early for new parts to be in production.
I suppose the most plausible explanation is that it's a button for a knockoff product.
The original iPhone was announced at a special event on January 9, 2007.
iPhone 3G was announced at WWDC 2008.
iPhone 3GS was announced at WWDC 2009.
iPhone 4 was annouced at WWDC 2010.
iPhone 4S was announced at a special event on October 4, 2011.
How soon they forget! It wasn't an Apple 'special event', it was the perennial San Francisco MacWorld Expo, once the go-to event for Apple announcements.
Apple's moved on from MacWorld as a launch platform, and I wouldn't be completely surprised if Apple someday owned their own general-audience conferences – believing, as with retail stores, they should control the whole experience.
But MacWorld Expo shouldn't be written out of Apple history.
It's possible that there are no new hardware products at all in the keynote (though maybe not likely), only a review of what Mountain Lion brings, maybe incldluding some new software (the aging iWork is desperate for an update) and a preview of iOS6. Remember: Apple used to have preview events for the next iOS early in the year. That did not happen this year, so they have to preview iOS6 at some point before they release it, likely together with a new iPhone.
The WWDC (World Wide Developer Conference) is aimed at developers, so it's not the right forum for major hardware releases. I'm pretty sure the mainstream media won't be present.
Except for the iPhone 3G, 3GS, and 4 at WWDC 2008, 2009, and 2010, respectively.