Apple previewed Mac OS X Lion, iOS 5, and iCloud. The three upcoming new releases were previewed during this year's Worldwide Developers Conference keynote, to give developers and users an idea of what to expect in the months ahead.

Mac OS X Lion:

Mac OS X Lion, the eighth major release of the Mac operating system, will feature more than 250 new features, including Multi-Touch gestures, system-wide support for full screen apps, Mission Control (which gives you a view of everything running on your Mac), the Mac App Store (for finding, downloading, and installing Mac software), and Launchpad (which keeps all of your apps organized in one place).

“The Mac has outpaced the PC industry every quarter for five years running and with OS X Lion we plan to keep extending our lead,” said Philip Schiller, Apple’s senior vice president of Worldwide Product Marketing. “The best version of OS X yet, Lion is packed with innovative features such as new Multi-Touch gestures, system-wide support for full screen apps, and Mission Control for instantly accessing everything running on your Mac.”

Other new features include Resume, which brings your apps back exactly how you left them when you restart your Mac or quit and relaunch an app, and AirDrop, which finds nearby Macs and automatically sets up a peer-to-peer wireless connection to make transferring files between machines easy.

Mac OS X Lion will be available in July as an upgrade to Mac OS X version 10.6 Snow Leopard from the Mac App Store for $29.99, and requires an Intel-based Mac with a Core 2 Duo, i3, i5, i7, or Xeon processor and 2GB of RAM. The Lion upgrade can also be installed on all of a users authorized personal Macs.

iOS 5:

iOS 5 will include over 200 new features that will be available for the iPhone, iPad, and iPod touch. The new iOS 5 features include Notification Center (a new way to view and manage notifications without interruption), iMessage (a new messaging service that lets you send text messages, photos, and videos between all iOS devices), and Newsstand (a new way to purchase and organize newspaper and magazine subscriptions). iOS 5 also allows users to operate their iOS devices PC Free, meaning they can activate and set up their iOS device right out of the box, and get software updates over the air with no computer required.

“iOS 5 has some great new features, such as Notification Center, iMessage and Newsstand and we can’t wait to see what our developers do with its 1,500 new APIs,” said Steve Jobs, Apple’s CEO. “Perhaps iOS 5’s paramount feature is that it’s built to seamlessly work with iCloud in the Post PC revolution that Apple is leading.”

Safari also gets an update, with the ability to save articles to read later, Tabbed Browsing, and more. Built-in Twitter is also being integrated into iOS, so you can sign in once and then tweet directly from any Twitter-enabled apps, including Photos, Camera, Safari, YouTube and Maps. The new Reminders app allows you to manage tasks easily, by creating and grouping related tasks together, setting time or location-based reminder alerts, and the ability to view reminders in iCal and Outlook.

iOS 5 will be available as a free software update for iPhone 4, iPhone 3GS, iPad 2, iPad, and iPod touch (third and fourth generation) this fall. Some features may not be available on some devices.

iCloud:

iCloud is a new set of free cloud services that work with applications on your iPhone, iPad, iPod touch, Mac, or PC to automatically store your content in iCloud and push it to all of your devices. When anything changes on one of your devices, all of your devices are wirelessly updated.

“Today it is a real hassle and very frustrating to keep all your information and content up-to-date across all your devices,” said Steve Jobs, Apple’s CEO. “iCloud keeps your important information and content up to date across all your devices. All of this happens automatically and wirelessly, and because it’s integrated into our apps you don’t even need to think about it—it all just works.”

The free iCloud services include the former MobileMe services - Contacts, Calendar, and Mail - which have all been completely rewritten to work with iCloud. The App Store and iBookstore now allow you to download purchased iOS apps and books to all your devices, not just the device they were purchased on, as well as view your purchase history. Apps and books can also be downloaded to up to 10 iOS devices at no additional cost.

Other features of iCloud include iCloud Backup, which automatically backs up your iOS devices to iCloud daily over Wi-Fi when you charge your iPhone, iPad, or iPod touch. Backed up content can also be restored if you replace your iOS device, by simply entering your Apple ID and password during the device's setup.

iTunes will also be coming to the Cloud, letting you download your previously purchased iTunes music to all of your iOS devices at no additional cost. New music purchases can be downloaded automatically to all your devices as well. Music not purchased from iTunes can use iTunes Match to integrate easily with the Cloud. iTunes Match is a service that replaces your music with a 256 kbps AAC DRM-free version of a track, then uploads a small percentage of the unmatched music to the Cloud, making the music available to you within minutes, instead of having to spend a lot of time uploading your entire music library on your own. iTunes Match will be available this fall for a $24.99 annual fee.

iCloud will be available this fall, and users can sign up for iCloud for free on an iPhone, iPad, or iPod touch running iOS 5 or a Mac running Mac OS X Lion with a valid Apple ID. iCloud includes 5GB of free cloud storage for Mail, Document Storage, and Backup. Purchased music, apps, books and Photo Stream do not count against the storage limit. iTunes in the Cloud is available now in the US and requires iTunes 10.3 and iOS 4.3.3. Automatic download of apps and books is available today. Using iCloud with a PC requires Windows Vista or Windows 7. Outlook 2010 or 2007 is recommended for accessing contacts and calendars.