Painful experience for the Keynote 6.0 and 6.1/ Pages 5.0 and 5.1/ Numbers 3.0 and 3.1 Versions.
The same updates showing up again and again. For Keynote, Pages and Numbers.
Download takes half day. During this time the three programms are blocked from usage as long as the "update" completes.
Few days later - same update showes up again.
MacBook Pro with Retina display, OS X Mountain Lion (10.8.2)