There are a lot of new features in Jelly Bean, not as many as was from Gingerbread to ICS, but still a lot, and yesterday they didn’t talk about most of them, it was just an overview of the really big ones like butter smooth UI or the new notifications.
The folks from Android Police have found one of those new features that we didn’t know about, and it’s a great one. It turns out that now you can disable the notifications by app. It doesn’t matter if the app has the setting to disable notifications or not, you can do it from the OS, just like disabling uninstallable apps, you can prevent an app from creating a notification.
Also, if you long press a notification, you get an App Info and it will let you know which app created the notification.
A really awesome and needed feature to fight notification spammers and such.
source: Android Police