It's not that simple!
Well, I took the time of doing some research on what the different companinies' attitude towards abandonware is. I mailed different companies to see what they say. Here is what I found out:
Microsoft hasn't responded (so far).
Activision regards all abandonware distribution of their games illegal.
EA generally regards it to be illegal, since many games out there on abandonware sites were not declared abandonware by EA. BUT, and that's interesting, some sites cooperate with them, including "The Keep" and "Home of the Underdogs". Their content is regarded to be legal by EA. Same goes for LucasArts and Inforgrames, by the way (although both sites don't have any LucasArts software up).
This is not intended to brake a discussion about abandonware loose. This site has a non-abandonware-rule, and I respect that and again apologize for braking it by accident.
But, my dear Wedge, it seems to me that it was rather naive of you to think that the abandonware question is that simple. There's no clear "black or white" here! It's more complicated!
Greetings
ButtSeriously