Officially, only CS2 owners should download those files and have the right to use them.
In practice anyone can as they work (for some definitions of "work" as many of CS2 programs have problems with later OS versions of both Windows and OS/X).
Legally, downloading those is not much different from downloading them from a torrent (apart for your own computer security).
In practice I doubt Adobe cares at all - someone using that version of CS2 is probably better of someone using a free competitor product or a pirated CS6 and more likely to upgrade somewhere in his/her life.
As an regular owner of Lightroom and CS5.5 Web Premium of which I use 10% of the paid programs, I think I can overcome my sense of guilt if I use that CS2 version of Premier Pro to edit the movies of my daughter, but to everyone what his conscience feels better
Just don't think downloading those is 100% legal unless something new from Adobe pops out.