A Taiwanese Mac news site with a history of accurately predicting future Apple products says Apple is currently testing three different prototypes of the next iPhone. From what can be gleaned from the Google translation, tw.apple.pro says one of the iPhone 5 prototypes features a a slide-out physical keyboard -- a form factor that Steve Jobs and Apple have never seemed too keen to embrace.
Another iPhone 5 prototype is said to closely resemble the current iPhone 4 with a longer-lasting battery and an 8 megapixel rear camera. The site suggests that if this prototype is released, the iPhone 5 will be to the iPhone 4 what the iPhone 3GS was to the iPhone 3G -- in other words, a spec upgrade, but with no external redesign.
There is no word on what the third prototype features. As AppleInsider points out, tw.apple.pro has a relatively solid history of producing rumors that turned out to be true, including the white iPhone 4, the iPhone 4's battery, the 2008 MacBook redesign, the new Multi-Touch iPod nano and the 2008 MacBook Pro's unibody redesign. However, in 2009 the site claimed that a 15-inch MacBook Air was in development, but that never materialized. This, of course, doesn't mean a 15-inch MacBook Air has never been in development -- or even prototyped. Given the positive track record of rumors from tw.apple.pro, it's reasonable to believe that just because a reported prototype doesn't make it to market, that doesn't mean tw.apple.pro's information was false.
So, is tw.apple.pro's report correct? It's possible, but if they are correct, which of the three prototypes will become the iPhone 5? Only Steve Jobs and a handful of people at Apple know for sure. The next iPhone most likely won't ship until June, so until then, there's plenty of time for more rumors and speculation.