A recent patent filing titled “Portable Electronic Device for Instant Messaging ” indicates that Apple is getting closer to adding its own instant messaging client to the iPhone.
The filing (US Patent 20080055269) covers methods for sending, receiving, and viewing ongoing conversations. The proposed GUI is similar to Apple’s current interface for SMS.
The application reads: “The GUI has a set of messages exchanged between a user of the device and another person. The set of messages (is) displayed in a chronological order. In response to detecting a scrolling gesture comprising a substantially vertical movement of a user contact with the touch-screen display, the display of messages (is) scrolled in accordance with a direction of the scrolling gesture.”
The application does mention SMS, but there are serveral references to “IM” and “Instant Messaging”. The patent application provides background on Instant Messaging.