That's the Internet for you :-p ... official Adobe response, see http://forums.adobe.com/message/4974662
On behalf of Adobe Systems Incorporated ...
You have heard wrong! Adobe is absolutely not providing free copies of CS2!
What is true is that Adobe is terminating the activation servers for CS2 and that for existing licensed users of CS2 who need to reinstall their software, copies of CS2 that don't require activation but do require valid serial numbers are available. (Special serial numbers are provided on the page for each product download.) See <http://forums.adobe.com/thread/1114930>.
You are only legally entitled to download and install with that serial number if you have a valid license to the product!
... so according to Adobe, even downloading is not ok w/o a license - but since there's nothing whatsoever after entering the Adobe ID on the download site, I don't think they won't annoy people who downloaded it with a "real" ID. As I said above: Someone's out of a job...
EDIT: I don't think Adobe could give away CS even if they wanted to because surely there are some included components licensed from 3rd parties that want to be paid per delivered copy, no matter what Adobe does - it's the same problem why many source codes cannot be published.