Ooh, horrible thought--Twitter is designed to be impermanent. Can Chaz and co. set up one of those twitter-repeaters to preserve their prose for posterity?
I suppose somebody with the time could transcribe them to the wiki.
I had most of the code for this from other projects, so http://jcberk.com/shadowunit/
now has a basic archive of our favorite agents. It'll update with any new tweets every hour or so, but if a new character joins and I don't notice, email me at firstname.lastname@example.org
to add them. (I'm happy to share the code, if someone wants to put this somewhere more official and/or improve on it....)