If the latest rumours are true, a 3G iPhone could be released as soon as January 2008. A Swedish carrier has apparently given one of its large customers assurances that it would receive the still-unannounced iPhone at the beginning of 2008, only months after the expected release of the iPhone announced at MacWorld 2007. This new phone would use High-Speed Download Packet Access (HSDPA).
The lack of 3G has been among the biggest complaints heard so far against the iPhone. Others include th closed system and the sealed-in battery. Should this rumour turn out to be true, it would help Apple compete on more equal footing in areas of the world where 3G is more widespread (namely Europe and Asia).
There are no hints yet on how this 3G iPhone would differ from the original iPhone aside from the addition of 3G (if at all).