First, the release notes are not an error. You guys on the forums are just ahead of the game and notice these sort of changes before most people.
We'll be doing the official change to TheBrain 8 shortly. Second, enkidu, everyone's price to upgrade to TheBrain 7 was different. The official base upgrade cost to TheBrain 7 from PersonalBrain 6 Core at the time of release was $59 and the base upgrade cost to TheBrain 7 from PersonalBrain 6 Pro was $100. Please keep in mind that we no longer have a Core version of the software and Core was much more limited in function than our current releases. Your PersonalBrain 6 Core license was purchased on 03/26/12 and TheBrain 7 license was purchased on 05/23/12. This is only a two month difference so you were able to upgrade at that base cost. It's been more than a year since that upgrade and you have a Pro Edition of the software so the upgrade is $99.