The best I could tell from the keynote was that an iChat-like interface was on SMS Texting. I don't think anything else was mentioned about IM of any kind.
you would think that the iPhone would have some sort of IM feature...i mean even the most basic phones allow you to use it and this phone blows them out of the water!
I know that iChat asks if you would like to use an AIM account as your iChat account, so as long as the iPhone has iChat, which I am not sure I will, you should be able to use AIM on the iPhone. The others, I am not sure of.