Many people believe that the PR update happened in Mid January but others beg to differ because they saw no changes and no signs of any type of update. If you are still waiting for the up coming PR Update, I wish you luck in the wait and I hope you have something productive to do rather than holding your breath.
Google really messed up how the PageRank System works and they have messed up the whole thing for web masters. Webmasters no longer look at PR when it comes to getting advertising space but rather look for how big the site is and how popular it is. I have given up hope in the whole page rank system that google has built up because they have gone against their ethics, so why should I believe what they are doing?