iMessage is one of the great new features of the upcoming iOS 5 update and now there is evidence that it may soon be integrated with OS X Lion’s iChat instant messaging software. This would enable instant messaging between iOS devices and Mac computers running OS X Lion.

iMessage is an iOS 5 messaging application which includes sending messages, photos and videos over WiFi or 3G. Messages can be pushed across all iOS devices that use the same account. You can even pick up on the conversation right where you left off when switching from your iPhone to your iPad or iPod touch.

MacRumors received some information today that reveals some new code has been added to OS X Lion’s iChat framework that points to integration with the iChat app and iMessage.

The "timeDelivered" and "timeRead' fields indicate the tracking of delivery and read receipts for instant messages. These features, however, are not supported in any of iChat's native messaging protocols, while the same features are offered in Apple's iMessage protocol. These properties were also not present in previous versions of iChat prior to OS X Lion. We believe the only reason Apple would have added these properties was to build in cross compatibility with their new iMessage protocol.

This does make a lot of sense and is something that has been strongly rumored earlier in the year too. I think it is only a matter of time before this all comes together and I would not be surprised if it was announced along with the official launch of  iOS 5.