I don't think this is a big deal, of course you're going to have a massive wave at launch and a load of those people are going to bounce right back off it. The

I don't think this is a big deal, of course you're going to have a massive wave at launch and a load of those people are going to bounce right back off it. The question is whether communities have started to form, because if even some small communities have started to form there that will slowly drag users back in as more features come online and more churn happens at Twitter. A social network can't really just come into being overnight, forming those communities, finding like-minded people takes time. The initial launch has done a great job of seeding the ground. The question is whether it grows and flourishes - and either way that'll take time to figure out, and it'd be silly to write it off given the incredible ability Facebook has to drive users to a new service.