It was updated on 03 May. Just because the pages on your site might not have changed their PR doesn't mean it didn't happen.
I am sure we will now get the usual run of "who cares about PR?" type comments I would just point out the frequency of updates in recent years: 2009 - 4 2010 - 1 2011 - 5 2012 - 2 so far which indicates that rather than doing away with PR, Google is publishing it more regularly and more often.