According to specifications provided by Apple on its website the iPhone 3G will require iTunes 7.7 and Mac OS X 10.5.4. So, we should not be surprised to have some software update before July 11th.
The new version of iTunes should open the door to the expected AppStore, one of the new functions revealed with the firmware 2.0.
When looking at the details about MobileMe, iTunes 7.7 is mentioned as well as the release of Mac OS X 10.5.4 while the minimal OS X version compatible with the successor of .Mac is Mac OS X 10.4.11.
[translation by Linathael]