AT&T's customer service representatives certainly aren't known for delivering accurate information about soon-to-be-released products. As such, the following should be taken with a grain of salt: we've received corroborated word that an AT&T employee memo lists MMS (multimedia messaging service) support -- allowing transmission of text, pictures, and potentially video to other MMS-enabled phones -- as a feature of the iPhone 3G.
Perhaps intriguingly, AT&T has yet to reveal any text message-inclusive data plans for the iPhone 3G. The original iPhone's data plan included 200 text messages by default, with more or unlimited messages available at higher costs. Could the omission mean a revamped, MMS-included scheme is in the works?