Apple gave users their first glimpse at iOS 5, the next iteration of the company’s mobile operating system for iPhones, iPads, and iPod touch models.

For starters, when you’re actively using your iOS device, new notifications no longer take over your screen and require you to deal with them. Instead, they appear in a subtle, smaller, animated bar that slides down from the top of the screen. If you tap the notification, you’re taken directly to the app that sent it; otherwise you can ignore the notification—it will go away on its own.

But instead of disappearing into the ether, notifications are now archived: iOS 5 also introduces something Apple calls Notification Center, a single place that combines all of your notifications. You can access Notification Center at any time with a single downward swipe from top of your device’s screen—a gesture which, it must be said, achieves the same effect already on Android phones. Notification Center then slides down to display a list—sorted by app—of push notifications you’ve received, including missed calls, voicemails, text messages, and app-specific notifications. Apple has also added stock and weather updates.Next came Twitter integration, which covers Contacts, Safari, Photos, Camera, YouTube and Maps. You can now Tweet from all those apps and your contacts are automatically synced with their Twitter accounts.

New iPhones will lose the traditional “Connect to iTunes” screen and instead display a Welcome screen—a quick swipe and you can activate your device on the device itself. Software updates—as in, new iOS updates—are now sent over the air, too, so you no longer have to connect a cable to your computer to get the latest incarnation of the operating system through iTunes. You also no longer need to plug your iOS device into your computer to sync media, and thanks to delta updates (which include only code that’s been changed), iOS-app updates will be much smaller.

iOS 5 includes a new messaging feature called iMessages, built into the Messages app, that lets you sends texts, photos, videos, and contacts—and supports group messaging—with other iOS devices. Different from traditional text messaging, iMessage messages can be sent only between iOS devices, and include new features such as delivery receipts, read receipts, and iChat-like indications of when your contacts are typing back to you. Messages are delivered to all your iOS devices, work over both 3G and Wi-Fi, and are encrypted, to boot.

Reminders were also unveiled, bringing all your to-dos together and allowing you to set-up, well, reminders. The good news is that the app is location aware so it can now remind you of events based on where you are. It’s nothing that you couldn’t achieve with an app anyway, but it’s always better when things come built-in (for free!).

The camera department got an upgrade, too, with a dedicated camera shortcut landing on the lockscreen and some settings finally making their way to the UI. You now get the option to add grid-lines to your viewfinder, lock exposure and focus by pressing on the screen and using the digital zoom by pinching in ala Galaxy S II.

The Safari browser was arguably the app to get the most significant update, but alas, those were mostly for its iPad version. The Apple slate got tabbed browsing, bringing it on par with the competition. The Reading list plug-in for both the iPad and the little iOS devices allows you to save pages for reading later. Those get synced between devices too.

Forstall said that “most of the major publishers of magazines, and many newspapers” have signed up for App Store subscriptions already. Newsstand is a devoted app for accessing and downloading those periodicals. The interface looks a lot like iBooks, only it focuses on magazines and newspapers instead. The app also supports background downloads—for example, new issues that arrive overnight will download automatically and be waiting for you in the morning.

In practice, Newstand behaves a lot like an iOS folder. As you can see in the screenshot below, when you tap the Newsstand icon, it doesn’t launch a true app; it simply reveals collected icons for your subscriptions.

According to Forstall, those are just a sampling of new features in iOS 5. He showed a slide packed with several others, including AirPlay mirroring to your Apple TV, Wi-Fi iTunes sync, new multitouch gestures to flick between apps, a new iPad Music app, personal dictionary support, hourly weather forecasts, typing shortcuts, alternate routes in maps, voiceover options, wireless sync for Exchange tasks, FaceTime mid-call invitation alerts, improved FaceTime video quality, mass configuration, real-time stock quotes, custom vibration patterns, accessible input for mobility, improved offline support in Mail, voiceover item chooser, an option to speak text, and finally, the long-awaited capability to set tones for voicemail, mail, and calendar alerts.

Forstall said that iOS 5 will ship to customers this fall, and it will support the iPhone 3GS and 4, the third- and fourth-generation iPod touch, and all iPads.