TUAW's code-scouring tipster is back with rumors on what could be found in an Apple iChatMobile app, and it's set to jibber with some Jabber:

[a] new XMPP framework has been spotten in the latest iPhone firmware. XMPP refers to the open source standard developed by the Jabber community for instant messaging. Remember back in March when Apple announced it would support native instant messaging? In a nutshell, it looks like Apple's new iPhone-based chat will be built on Jabber/XMPP. [...] Unfortunately, we're told that this XMPP support remains in a private framework and will not be available to 3rd party SDK developers.

How (and if) this fits in with the recently discovered Apple chat-related patent filing, and/or (double if) the AOL concept demo from the SDK event, is anyone's guess at this point, but one thing's for certain: it's getting interesting in iPhone IM land!