I promise this will be the last post I make for a while regarding Google Slaps. However, I do want to summarize a few observations now that the dust has settled somewhat. Who knows, not that any of this is solid evidence of anything, but sometimes you can glean a bit about how the internals of a black box work by observing the effects of external stimulii on the behavior of the black box.
Since there really appears to be little consistency in how Google Slaps are administered, especially this last one, my theory (gut feeling) is that Google goes through these events to periodically clean out their advertising inventory.