Sure it may not happen right away, but one developer has already found evidence pointing to a future compatibility between iMessage on iOS devices and iChat on Mac OS X computers. The snippet of code leading to this conclusion revealed two new properties in OS X Lion's version of iChat software.
These properties could be the beginning of Apple adding full support for iMessage to iChat instant messaging. The "time delivered" and "time read" fields are not used or needed in iChat, however they are already used by iMessage to track instant messaging. According to MacRumors Apple would have no other reason to add these lines of code.
Live video iChat on the iPhone may be something we would expect from Apple, but is the timing and technology ripe for this functionality to come out this summer? Some reports are reading into AT&T network upgrades to 7.2 Mbps as a sign that they are bracing for more bandwidth demands from their iPhone subscriber base, and that one of those demands could be live video chat.
The longer AT&T can deliver what Apple needs for its hardware, the longer the company stands to profit from an exclusive arrangement to offer the iPhone on its network. Other leaks and data that point in the direction of a front facing camera on the next generation iPhone have also surfaced.