In his during Monday’s WWDC keynote, Apple executive Scott Forstall highlighted just ten of 200 features slated for this fall’s iOS update. And with many of those changes addressing the operating system’s glaring weaknesses, I’m confident that will wind up being the best thing to happen to Apple’s mobile OS since its creation.

The iPhone and iPad were indisputably revolutionary devices. I don’t fault Apple for needing time to figure out how to perfect things. iOS 5 seems to be focused on writing wrongs, taking great strides on usability, and focusing intimately on the user experience. Of course, focusing on user experience is at Apple’s core, but iOS 5 strikes me as exemplifying a dramatically rekindled interest in that pursuit.

Far and away, the biggest annoyance in the post-push alert iOS world is the handling of notifications. Those dopey blue alert boxes steal focus from whatever you’re doing and require interaction. They interrupt me, they confuse my kids, they stop my video playback… In short, they stink. iOS 5 may not reinvent how to handle mobile notifications—it clearly takes some cues from previous implementations on Android and elsewhere—but will be a welcome and indisputable improvement to the iPhone and iPad experience. In fact, calling Notification Center an improvement is akin to calling the iPad an improvement on the calculator.

Notification Center—coupled with iOS 5’s floating banner alerts—redefines what it means to get notified on iOS, and removes all the frustration from that process. The lock screen integration is also brilliant: New notifications will stack up on your lock screen if they come in while your device is asleep. Perform the “swipe to unlock” gesture on an alert, and you’ll launch the appropriate app instantly. It’s terrific.