There isn't any change yet, the last confirmed Google pr update was on 02 April 2010 http://googlepagerankupdate.com/
It is common for a site that gets the change from PR N/A to PR 0, which means that your site has been indexed by Google normally and absolutely.
It's a minor "update"... which means random pages get updated at random times and most pages (and whole sites) get passed over. Which means we get to compare sites that were just updated with sites that have been stuck at the same value for a year or more. And where well-maintained, complaint, but new sites have the same PR0 value that penalized sites have. Maybe one of these days Google will wake up one of these months and notice that the whole idea is drifting off into a slow descent into chaos...
These minor "updates" just fascinate me. Update 2% of pages and call it a month. Wish I could get away with that.