Here is a look at the rumors, possibilities, and ideas of what may be included in iOS 5.
Beyond iOS 4
iOS 4.1 was just released and people are awaiting the announced iOS 4.2, but there is still a great deal of anticipation about what will be included 
in iOS 5. iOS 5, which will likely be released at the same time as the iPhone 5, will be the next major overhaul to the iPhone’s operating system and will bring with it a whole number of different features that should be new to the device. Some of these new iOS 5 features will be specific to the iPhone 5’s technology, as the iOS 4 was to the iPhone 4, and some will be more relevant to older iPhone models like the the iPhone 4 and iPhone 3Gs. Here is a preview some of the rumors and conjecture around what might be delivered with the release of iOS 5.
Push Upgrades
As many of the applications have developed, social networking and IM apps have become standard, and new iTunes features like Ping and Air Play have changed the way people use the iPhone, the infrastructure software needs to evolve as well. This means that the Push Notifications need to grow out of the simple binary format that they have had since the early days of the iOS. What we can expect out of Push Notifications in iOS 5 is not concrete, but we can at least hope for a much more specific form of Push notification.
Extend and Fix Multitasking
Multitasking has been great in theory, but the execution has not really been quite as stellar. An overhaul would be warranted in iOS 5 that would perhaps allow iPhone apps to work together a little more seamlessly. For example, the text message function could allow you to answer an incoming text message when you are working within an app instead of switching over. The iPhone folders could actually hold more items, perhaps up to sixteen or more. Overall the iOS 5 is almost certainly going to update the multitasking features now that Apple has had a chance to hear from customers, but the specifics of how this customization will hit iOS 5 are still unknown.
Integrated Apps
Along with the extension of the multitasking feature there could be an integration of a whole other range of features so that identifiable services could be brought into interaction with iPhone device specifics. For example, weather delays for your area could pop up using the changed iOS 5 Push Notifications and then allow for that to change your Calendar items. News updates could be filtered onto your iPhone and all of your social networking tools could begin to be integrated with their own intractable features. This would be especially true with the interaction with the Maps function, which should have elements that could be linked with every other app. All of these are relatively vague, but we can see with iOS 4 that Apple is trying to integrate all of these features and we can expect another step towards this with iOS 5.
4G Network Compatability
The main thing that people expect concretely is for the iOS 5 to support a 4G network, which AT&T has been promising for 2011. Obviously the iPhone 5 will support this with its iOS 5, but there will likely be iOS 5 4G network compatibility for earlier versions of the iPhone like the iPhone 4, iPhone 3Gs, and even the iPhone 3G. The 4G network will mark one of the most important steps forward for the iOS as the largest upgrade to the iPhone’s data network since the iPhone 3G. This iPhone 4G network will also hopefully be supporting FaceTime so that it does not require the use of a Wi-Fi network. The 4G compatibility marks the top of most iOS 5 wishlists.
RFID
Though many of the features of the iPhone and the AT&T contract with data plan have already given privacy advocates enough to cringe over, many people have begun to speculate that the iOS 5 will support RFID features. These iPhone RFID features would really only be in line if the actual hardware of the iPhone 5 would support it, but if it did then this would be the jump needed to allow the iPhone to serve as your credit card, car key, or medical identifier tag.