Apple CEO Steve Jobs has announced the arrival of the path-breaking cloud service iCloud and an upgrade iOS 5 at the WWDC 2011.

More than the launches, the statement that Jobs issued at the conference is pivotal: We're going to demote the PC and the Mac to just be a device - just like an iPad, an iPhone or an iPod Touch. We're going to move the hub of your digital life to the cloud.

With a single stroke Apple announced the death of the desktop by cutting the umbilical cord which kept the iOS devices attached to the Mac.

However, the iOS 5 also ushered in a key feature which spells doom for RIM's BlackBerry Messenger (BBM) triggering an exodus of users from the BlackBerry camp - primarily college students.

Apple's iOS 5 has been endowed with a feature called iMessage, which allows users to send unlimited text messages to other iOS devices like iPad, iPhone and iPod. The feature is baked into the Message apps, thus, enabling users to send text, photos, videos, locations and contacts.

The feature also allows users to track the messages sent through read receipts and delivery recipes. The service adds a unique feature in which a user can see in real-time when someone is responding to a message.

It also adds encryption and group messaging to the service. The key to success of the feature is the iOS 5's push notification feature which collates all notifications like e-mail, texts and friends' requests at a single place in the Notification Center. A user has to swipe down from the top of the screen to enter the notification display.

The service is a direct attack on RIM's BBM service which allows a similar feature like iMessage. RIM's BlackBerry phones have been a mainstay of corporate primarily because of the secure e-mail service that RIM provides. However, the phone was also adopted by the college going clientele because of its BBM service.

It's likely that Apple has dealt a death blow to RIM as iMessage could now appeal to the same segment.

iMessage also does not bode well for carriers like AT&T and Verizon as SMS forms a key component of their revenue. Apple with around 200 million devices could certainly dent the carriers' revenue with much of the iOS-to-iOS device messaging facility now available for free.

Given the ubiquity that Apple's devices enjoy, blogger Anil Dash, rolled out a piece asking when Apple will launch its own Twitter like platform. He argues that Apple has the necessary infrastructure to deliver such a service. Apple has client app software on millions of devices, a large-scale real-time messaging service in the form of Apple Push Notifications, account information of every client like credit card information in iTunes and experience in making client apps.

However, Apple has gone the other way and partnered with Twitter, whereby iOS 5 would allow users to tweet directly from Safari, Photos, Camera, YouTube or Maps.

Whether Apple will launch its own Twitter-like network is subject to conjecture, but certainly its iOS 5 will kill SMS and RIM's BBM.