I'm assuming that if he asks them to, Archive.org will remove it from their archives?
Disclaimer: I don't know anything about Stepwise or the author, so hopefully I don't offend anyone.
Things like this and the disappearance of newmogul.com make me nervous about the ability of one individual to destroy knowledge on a whim. It might be useful to have offshore archive centers where it's harder to get rid of stuff like this. Yeah, I know this was the property of this one guy, and he has the right to destroy it, but something about it doesn't sit well. Sites like this seem to be a collection of knowledge from many different people, and it's a bit disconcerting to see it disappear overnight.
What if archive.org decided on a whim to disappear into the night? That's a lot of knowledge lost.
Maybe the answer is decentralized archival in general. Some kind of opt-in network where people agree to store a bit of the internet on their machine. Hmm...in fact, we already do this with caching. Maybe some kind of browser plugin that makes use of those cache files for decentralized archival purposes?
Sorry...rambling a bit. It's an interesting problem.