As seen in the video above, Yosemite's revamped Notification Center has more in common with iOS 7 than it does OS X 10.9 Mavericks. In fact, it looks nearly identical to the mobile operating system's version save for Yosemite-exclusive fonts and tweaked transparencies.
With the addition of a "Today" pane, which is the default view for Notification Center in Yosemite, users have quick and easy access to upcoming events, current weather, Reminders and much more. Like iOS 8, the assets are referred to as widgets and fulfill many of the duties carried by the current OS X 10.9 Mavericks' Dashboard.
The term "widgets" isn't thrown around lightly as Apple is allowing developers to build Notification Center support directly into their apps. With Yosemite, instead of navigating to the Dashboard, users can check sports scores, punch in calculations and reference world clocks directly from an active desktop.
Importantly, Apple is streamlining the coding process for developers to integrate Notification Center support for both Yosemite and iOS 8, meaning widgets will be truly cross-platform once the operating systems hit this fall.
In the developer beta, only first-party apps like Stocks and Calendar are supported, though SVP of Software Engineering Craig Federighi demonstrated the feature's potential at WWDC via a variety of third-party software like ESPN SportsCenter.
Apple has also tied in and expanded Mavericks' share button in Yosemite, giving users the option to access Messages straight from Notification Center. In Yosemite, the ability to message contacts is baked into the "Social" widget that also has hooks into OS X Internet Accounts like LinkedIn, Facebook and Twitter.
The system is not yet unified, however, meaning messages are posted in Today view, while notifications pop up in the separate Notifications pane. Notification Center does have the ability to respond to direct messages, email and SMS, but for now the mechanism is limited to the Mavericks-style pop-up window.
Other widgets are more interactive. For example, completing a to-do in Reminders will automatically clear that task from all devices registered to a user's iCloud account.
Finally, Yosemite's Notification Center will carry over "Do Not Disturb" settings from Mavericks, limiting the situations under which notification pop-ups appear on the desktop.