Retro Software has at least one used copy of Forsaken for $5.00:
http://store.retrosoftware.net/12713.html
A few weeks ago they actually had some new copies for the same price, so it might pay to watch this site if you want a retail copy.
Forsaken (used)
I have never heard of an announcement from Acclaim Entertainment to that effect, and I don't know who (if anyone) has purchased their intellectual property in the bankruptcy proceedings. That is the point that Kyouryuu was trying to make in the Forsaken Revival thread (i.e. that the game hasn't been officially made freeware).
The installer pointed to in the Descent MP thread actually points out that it's a cracked version. I don't think it was ever released for free officially although, like most old games, it should have been. It's either players releasing it for free, or under the impression it could be (like when Descent 1 was released "for free" on a magazine CD).