Inside the framework of Lion's iChat software are two new properties, related to delivery of messages, and verifying whether a message has been read. These features are not yet natively found in iChat, but are major components of iMessage, which will be a part of iOS 5 for iPhone, iPad and iPod touch.
The discovery of strings of code for "timeDelivered" and "timeRead" has led MacRumors to speculate that Apple could eventually bring support for its iMessage protocol to iChat. Currently, iMessage is only officially announced to work between iOS devices.
Of course, Apple first introduced its FaceTime video chat standard with the iPhone 4, but eventually brought a special FaceTime for Mac application to the Mac App Store earlier this year. That software allows iOS and Mac users to video chat with the FaceTime protocol.
Based on that, it would not be a stretch for Apple to bring iMessage support to Mac, whether through its existing iChat software, or with another standalone application like was done with FaceTime.
iMessage is a new proprietary chat client that will debut this fall with the launch of iOS 5 for the iPhone, iPad and iPod touch. It allows iOS-to-iOS chat and sharing of media in a manner similar to Research in Motion's BlackBerry messenger.
The iMessage software is based on the same push technology that Apple developed in-house, and has used for iOS application notifications, push e-mail and contacts. It uses an IM-like system to deliver messages and notifications to users on their mobile devices.
In addition, for iPhone users, iMessage will also replace the native Messages application and handle text messaging as well. Both Apple's iMessages and traditional cellular text messages will be sent and received through the software.
When Apple officially announced iMessage as part of iOS 5 in June, the reveal was said to have caught wireless carriers off guard. Fees associated with text messaging and picture messaging are a very profitable part of doing business for wireless providers.
With iMessage, users of iOS devices can be notified when their friend is typing them a message, and will also be able to see if a message has been received. Users will know if a message is unread with a "waiting for delivery" prompt, and iMessages are distinguished from regular text messages by being displayed in blue rather than green.