Abandonware is a legal grey area. What it comes down to is whether there is anyone left to prosecute: Nabbing old Microsoft stuff is likely to bring the wrath of Microsoft down on you, but downloading games made by a company that went bust in the early 90s is certainly justified.
Some is, some is less clear-cut. Some of the bigger abandonware sites are very careful to ‘pull’ games at the first sign of a legal threat, yet claim other titles are being displayed with the original author’s permission.
Abandonware falls into teh “its technically illegal but nobodys going to nab you for it” areas of law.
When you look at it carefully, what your really asking is do the publishers of this software want to deliberately destroy all traces of it?. For most publishers, I would guess that the answer would be NO, they simply dont care what happens to it.
If you really wanted, you could find the copywrite holder of the software and offer to paypal or mail then $5 for the software. Im sure most authors would be willing to grant you exemption for that token amount.
BTW: it is NOT illegal to dl abandonware providing you have the original disks which Cnet seems to imply that it is.