Toby Fox – @gRegorLove 5 years is too easy! Even if our exact URL structures changes, as long as it exists in our database (which we take very seriously) it will be exposed on our site and you'll be able to use our search, or scroll through the dialog archives at http://digg.com/tag/dialog until you find it, and Google will index it for search too.
The real challenge is a 100+ years, and for that we may have to rely on the Wayback Machine and other efforts. The URL this dialog lives at has all these comments. When the Wayback Machine hits http://digg.com/dialog/adrienne-lafrance-digital-rot in a few months, it will grab a snapshot of this discussion and, at this point, that's about as good as it gets on the Internet.
gRegor Morrill – Unfortunately not very surprising: this digg.com URL discussing digital rot did not even last 3 years. It redirects to the homepage now. Despite Toby’s response, I cannot find it using their search.