We recently learned of the multitouch gestures that will be making their way to the iPad with iOS 4.3. They won't be coming to the iPhone, at least not as far as we know (based on the features in the iOS 4.3 Beta).
Someone was able to get those multitouch gestures working on the iPhone. The video above makes it clear why Apple probably wasn't ready to add that functionality to the iPhone and iPod Touch.
As far as new features coming to iDevices with iOS 4.3 goes, you can check out our list of new features that have been discovered so far. Check them out here.