I was looking where the upgrade to 6 was as I never clicked buy since it appeared to be the full version at $700.
Well, if you currently have CS6, you can easily get the latest available upgrade just from the Help menu, there is no cost for those on-going upgrades!
'Course for those with, say, CS4/CS5, maybe even CS3, the cost for upgrading to CS6 is what, about $350? I dunno, upgrading to the latest upgrade of CS6 is just Help/Upgrades! I believe it upgrades ACR as well...It's been a while!