In chapter 352 of the Apple vs. the world patent saga, a tale of push notifications violating a Motorola patent is the topic. Moto is apparently asking a German court to force Apple to stop said notifications in their MobileMe and iCloud products effective immediately. It appears as if Apple has no choice in the matter and has already issued a message through their support forums to German customers, informing them that push notifications for those two services are no longer available.
To give you a bit of a background, just understand that push notifications are those that appear from services like email or Twitter the second you receive something new. Without a push notification enabled in a service, you would either have to manually refresh your app to see what you have that is new or set up your app to automatically refresh every so often. Push notifications are not essential, but they do make life a hell of a lot easier.
Apple has already appealed this ruling.