The infamous PvP patch which has been pushed back more times than anyone cares to think about.  The current date for this to go live in Age of Conan's live servers is September 10th.  While the patch is largely a fix to PvP and how it works or in some cases does not work right now, there are other aspects which are stirring considerable debate. 

The Gem Nerf is a sore spot for many players who spent considerable effort trying to acquire a great set of gems for the purposes that they wanted, but now the gems may very well have been reduced in potency dramatically, making all of their previous effort in obtaining the gems a waste of time basically.

The continued imbalance of some classes and the various feats and abilities that still do not work after this many patches.  This could very well be the worst problem the game has, the broken aspects of certain classes.  Quite a few players have stated that this is the patch that makes or brakes their AOC Careers, so this patch may have an impact on server populations if the rumors hold true.

Now will it be enough to pacify the masses?  I guess we will all find out September 10th although you can go check the Testive server yourself for a preview of what is to come.  Good luck!