A few of those future PR scripts are reliable, especially the one that checks multiple Google datacenter IPs like these two:
http://www.mypagerank.net/googlecheck.html
http://www.seologs.com/pr-check/pagerank-dc.html
Shows PR4 on a few IPs for my site
www.trashylinks.com, and shows PR0 on the rest. Generally that indicates when the Toolbar PR export is completed, the site will be PR4 (up from PR0).
