The Boy Genius is reporting, via one of his “trusty Apple connects,” that iPhone OS 4.0 will feature, among other things:
• Multi-Touch™ gestures OS-wide
• “A few new ways” to run applications in the background — multitasking
• Update available for only the iPhone 3G and 3GS, but will “put them ahead in the smartphone market because it will make them more like full-fledged computers” more than any other phone to date.
More info and features in the full article here.