Well, not quite. In the US Copyright Office's list of exemptions from the DMCA's anticircumvention measures, there is this tantalizing exemption:Computer programs and video games distributed in formats that have become obsolete and which require the original media or hardware as a condition of access. A format shall be considered obsolete if the machine or system necessary to render perceptible a work stored in that format is no longer manufactured or is no longer reasonably available in the commercial marketplace.
The impetus for this exemption was a campagn by Brewster Kahle to preserve old programs stored on deteriorating hardware and media.
The Copyright Office's exemptions prompted speculation about the possible legalization of abandonware. But that seems unlikely. The definition of abandonware is much broader than the rather narrow language of the exemption: given (1) the broad spread of Windows and, until XP, its dedication to backwards compatibility, and (2) the fact that abandonware is sometimes construed as liberally as "any software more than four years old that is no longer being sold or supported, most software generally considered abandonware today would not be exempt from the DMCA.
More importantly, copyright law still lies behind all of these exemptions. What this means is that you can no longer be sued under the DMCA for circumventing the copy protection on your own 5-1/4" disk or Super Famicon game cartridge in order to transfer the data to your computer--but copyright law probably still prohibits you from distributing that file to other people.