We apparently still haven't seen everything that Apple has prepped for us in the next generation of iPhone OS as some new exciting tidbits are making their way to the web today.
First up Chatkit. Chatkit is a new framework present in iPhone OS 4.0 that underlies and further confirms Apple's rumored iPhone iChat client.
According to the present files, it looks like iChat for iPhone will be very similar to the present SMS app with the addition of some extended data detecting and sharing features. You'll be able to share through iChat links to maps, contacts, phone numbers; as well as file attachments like photos or videos.
On top of that, it works in the background apparently so you'll be able to stay connected at all times. I wonder whether Apple will open this up to other IM clients. I mean, if only Apple's iChat client is allowed to run in the background, this will cause quite some fuss.