DSA 1571-1 - New openssl packages fix predictable random number generator
For more info on the debian security announcement see:
http://lists.debian.org/debian-security-announce/2008/msg00152.html
Server keys for this host have been updated - any ssh users may well need to remove the old ones from their .known_hosts file (or equivalent). Just to let them know that the keys are changed and intentionally so.