Very related:
https://news.ycombinator.com/item?id=5305073 A tech from Posterous got in contact with members of ArchiveTeam via Twitter
https://twitter.com/vincentchu/status/308467595416334336 and then joined IRC:
http://pastebin.com/YB0emvnYTL;DR Posterous and ArchiveTeam are working on a way to backup Posterous before the deadline without accidentally DDoS'ing it.