Apple rumors need nothing to start. It just takes a not so crazy apple fan who can think of crazy things that Apple can present.
Add to this Apple’s habit to surprise people. The biggest of them all is the Macworld 2007 when the original iPhone was demoed by Steve Jobs. Not too long ago i.e. some 7 years back a small press conference was where the first iPod was displayed. And today both of these products rule the market.
The amount of fan base that Apple holds is more than its users. Not all Apple Fans can afford their products. This puts them in a semi-premium zone.
So no surprise that iPhone Nano, iPhone Pro and many such rumors keep popping up, often by reputed sources.