At today's announcement of iPhone OS 4.0, Apple unveiled seven major features in the latest version of its OS.

Most of these additions came as no surprise, in fact, many were what we wanted when iPhone 3.0 debuted last year. And the majority of these new additions aren't exactly revolutionary, like multitasking, for example; most of the features announced today already exist in various forms in other mobile operating systems. This raises the question: Is Apple pushing its mobile OS into the lead once again, or is it merely catching up with the level of innovation now being offered by challengers like Android and Windows Phone 7?

And will Apple's implementation of these features into the phone be better than that of its competitors? The answer to that last question might be Yes: I was impressed with how intuitive and tightly integrated the new features are in the OS. Of course, we won't know who does what better until we actually take iPhone 4.0 for a spin (same for Windows Phone 7, for that matter). For the sake of brevity, I will focus on how the iPhone 4.0 operating system compares to the various flavours of Android and what we know about the Windows Phone 7.

Multitasking

At last, the iPhone gets full multitasking (well, not the iPhone 3G and 2G, unfortunately). iPhone 4.0's multitasking system is incredibly simple and clean, and according to Apple, won't be a drain on your iPhone's battery life. To see your open apps, you simply double click the home button and a "dock" showing all of your open apps will pop up at the bottom of the screen.

All of the mobile other platforms have some kind of multitasking system, though some are more elegant than others. Visually, I like the Leap feature in HTC's Sense interface for Android, which lets you pinch to view seven thumbnail versions of your open pages. From there, you can go to any of those open applications. I also love Palm webOS' deck of cards system of multitasking as it is visually striking and easy to use, but it does seem to be a drain on battery life and performance.

Customisation

Predictably, there's no support for live widgets (ala Android or Symbian) in the new OS. Nor is there a home page you can customise with said widgets. That's not necessarily a bad thing, though it does limit the level of customisation on the phone. I was very pleased, however for folder support in Apple's new phone OS: You can organise your apps into folders by category by dragging and dropping them into each other. The iPhone will automatically assign a category name for them.

The iPhone also gets personalised wallpaper with OS 4, but that's another feature (like multitasking) that should have been there a long time ago.

Notifications

I was disappointed that Apple only made a slight tweak to the notifications system. I find the current system a bit disruptive, and I don't like the fact that there's no place to save or store your notifications. Both Palm and Android have fairly unobstrusive notification systems, and both let you see all of your older notifications. On the other hand, iPhone 4.0 will have a new service called local notifications, which don't rely on a third party server. So if you have a TV Guide app, and you want to be reminded of when a show comes on, you can have it send you a notification.