tedster - 10:01 pm on Jun 7, 2012 (gmt 0)
Interesting. The item below goes beyond what Matt Cutts tweeted at the time:
Improvements to Penguin. [launch codename "twref2", project codename "Page Quality"] This month we rolled out a couple minor tweaks to improve signals and refresh the data used by the penguin algorithm.
The data refresh was all that he mentioned, not the "minor tweaks."