If you are a cross platform developer who uses any sort of push notification you have either used or at least considered Urban Airship. They abstract the push interface and allow you to centralize your push notification system instead of configuring it for every system. Urban Airship already supports BlackBerry OS 7.1 and earlier along with iOS, Android, and more. Since Push Services did not change from BlackBerry 7.1 then Urban Airship already works with BlackBerry 10 but what is missing is a BlackBerry 10 client. Garett @RIM just posted up a notification today that RIM has put up a BlackBerry 10 Urban Airship sample app in GitHub using Cascades so you can check it out.
There are also some small changes in the permissions required to do Push on BlackBerry 10. You need to get your code signing keys provisioned to allow push. RIM says this is because of the power of push which allows developer to launch their application on your device. Here are the details. In a final note RIM has also added BlackBerry Push Services support to the Android Runtime for BlackBerry 10 Beta 4. That means devs can utilize push in their apps now. Details here.