Apparently, Adobe are turning off their authentication servers for CS2 related products.
When trying to activate your Creative Suite 2, Acrobat 7, or Macromedia products you may receive an error that the Activation server is unavailable. As of December 15th the activation servers for these products will be shut down. The specific affected products are as follows:
So that existing licensed customers aren't disadvantaged in the event that they need to reinstall, they have provided some new license keys which don't require activation along with some download links for the software installation.
I know a few people who needed to reinstall their Photoshop CS2 software who verified that the provided keys work.