This is the notification that pops up from the App Store on Mountain Lion:
As you can see, the only options are Details and Update. Most of these banners have a 'close' button, to dismiss the notification without taking an action. On this one though, it seems like the only action I can take is opening the App Store with it.
Just clicking the
x in the Notification Center list doesn't get rid of this actual notification.
How can I close this without taking the time to open up the App Store?