And since I can't comment on one of the linked entries without joingin the community, I'll comment here. The backend infrastructure that is mentioned will almost certainly be memcache, so not so much about replication of LiveJournal features there (unless you consider being fast and not crashing a feature).

Not to say that Vox isn't a copy of LJ with different marketing. It probably is. I didn't get far enough to find out, though, because the site design was too horrible for me to look at for more than a minute. Just saying that that comment shouldn't be used as evidence.