I haven't noticed any PR change on any of my sites I do notice a funkiness to backlinks though, with sites/pages showing that they are coming into my site even though I can't find any links on those pages, even cached version... Weird.
nothing change, it just a glitch. its true google update pr more often these day, and baclink also. My site with more than 200 BL suddenly got 10 BL today....arghhh..
to increase page rank, u need to build strong back link from various activities which give pr juice to your site.