It's almost 100 days since Google have updated PR, before that it was very often. Previously, Google's stuff have been talking about intention to decline to PR. I'm afraid if it happens - absense of PR will cause inaccuracies and leaps in the SERP of Google. Does anybody know - will be updating of PR at all?
'Toolbar' Pagerank - the PR you can see, lags behind what is being used in the algorithm. The changes in your PR and the effect that has, if any, in serps, happened long before you know about any PageRank 'update'. I wouldn't be at all surprised if Google stopped telling webmasters what their Pagerank is, wouldn't mean they weren't still using a version of it behind the scenes.