Split screen functionality is something that Microsoft has used to target the iPad in advertisements for its tablet efforts, and something that is often requested by users in forums and editorials. The feature in iOS 8 would allow two apps to be used side-by-side, but also make it possible for people to drag images, video and text from one app to the other. Apple is also working on a way to let apps running next to each other interact directly while running.
iOS 8 looks to be featuring a lot of improvements, including the possible introduction of a Healthbook app which would work with fitness and medical devices, and improvements to Maps with the addition of transit directions. Some of this could be pushed back to an iOS 8.1 update, 9to5Mac cautions, but overall, it looks like the next update will still bring a vast number of changes.