Page is a not externally linkable
tedster - 2:36 am on Mar 11, 2011 (gmt 0)
There's just a very small buzz about a PR Update on Twitter - and when there's a general PR Update, we usually see a flood of tweets. So I'd guess that it's one of those small PR export trickles that happen once in a while.
There was a major PR update at the end of January 2011 - 6 weeks would be a very short interval.