WWDC - the Worldwide Developers Conference - begins Monday, June 11 and opens with Apple's annual keynote. While an iPhone 5 reveal isn't impossible, the announcement of iOS 6 - and its changes - is highly anticipated and more likely.

Facebook Integration

The most likely feature; Apple's CEO, Tim Cook, said at All Things Digital D10 conference to "stay tuned" on the social network being integrated into iOS, like Twitter. Currently apps display a pop-up window to sign into the service, which is slow, and being able to post a status and attach a picture with it would be quicker.

Rumors suggested the two companies are working out the specifics of sharing, as users have different privacy settings on Facebook.com.

New Home Screen

The home screen and app-based grid layout in iOS has been incredibly successful for Apple since debuting in 2007, because of its simplicity and speed. However, some users and developers are calling the OS "boring." With a 4-inch iPhone 5 rumored, increasing the screen size to accomodate five rows of icons could be seen as underwhelming. A refresh is needed to take full advantage of the increased bigger display.

Improved Multitasking

Multitasking in iOS 5 is functional, but it requires a double tap to open the multitasking bar, a swipe to navigate through apps, a tap to close the app and another tap to close the multitasking bar. It's tedious, especially if the Home Button isn't reliably working.

Leaked builds pre-iOS 5 showed an Expose-esque multitasking interface, where the apps were represented as cards and displayed across the screen. A 4-inch screen could lend itself to displaying apps as cards, something a 3.5-inch screen may have found difficult.

Ability to Set Third-Party Apps as Default

A frustrating limitation in iOS is the ability to not set utility apps, such as e-mail clients like Sparrow, as the default. It's probably due to Apple wanting to control the experience, but when the Mail client is limited people look for better solutions to use as the main app. Apple needs to give the user some control, even if only specific types of apps can be set as the default.

Try Before You Buy

Downloaded an app you didn't like, but had to pay for it? The problem's solved if there's a demo version. Imagine downloading a trial version of an app that last half an hour, and then prompted you to buy the app or continue playing the trial. It would be a very limited, focused version of the app. For games it would be a no-brainer, and would give users the power to decide what's worth buying.

Move Multiple Apps Together

Dragging an app across a screen when not connected to iTunes is painful, and can take a while. A simple ability to select multiple apps at once, and even zoom out and press a home screen rather than dragging across, would be a simple and effective change.