... from the Dreamwidth staff is that it's believed the DDoS against LiveJournal is targeted not so much at LJ itself, as at Russian bloggers who post on LJ.
Keep in mind, by the way, that having a Dreamwidth account doesn't mean you have to stop using LiveJournal, as one commenter imputed. For about the past year or more, I've been making ALL of my posts on Dreamwidth — even though LogJam still doesn't work quite as well on Dreamwidth, and can't re-edit Dreamwidth posts — and having them automatically crossposted to my LiveJournal account. One benefit of this, in addition to redundancy, is that I don't have to keep retrying to find a time when LJ is responsive to make a post. Dreamwidth's servers will retry the crosspost for me. So when LJ is under DDoS, like now, I can post more reliably to LJ via Dreamwidth than I can directly.
So, for those commenting that offering Dreamwidth invites is helping the DDoSers: Think it through.
(Of course, replying to comments is still problematic...)