As I understand it, these are for if you need to reinstall, because the old activation servers for CS2 are being shut down. These "new" versions only require the serial number.
It could be argued that this is also a bit of a marketing ploy. They are after all eight year old versions of the apps. Adobe may be trying to see if anyone will upgrade to CS6 or "Creative Cloud" after having tried the "free" versions. I consider the fact that they are still available to be tacit acceptance by Adobe that anyone else could download the software. Realistically, anyone that is still using CS2 or already not a customer isn't much of a loss for Adobe anyway, and if it makes a new customer it is good for them.