ClearLockNotifications si NCQuickDismiss there are two tweaks available in Cydia for several months, and today their developer updated them to make them 100% compatible with the new iOS 6. The first tweak allows you to quickly clear all notifications from the LockScreen, and the second one adds a button to close iOS notification banners, and a second button to quickly close the Notifications Center. Both tweaks implement features that Apple doesn't want in iOS, and both can now be used on iOS 6.
ClearLockNotifications and NCQuickDismiss are available in Cydia's BigBoss repo.
