Scoble brings up something that isn't a problem for me (at least, not at the moment) - losing access to your content:

December 15, 2000. That’s when I started blogging. In seven years a lot has happened. The first two years of my blog have disappeared. They might be on a hard drive somewhere, I’m still trying to track them down.

I started later, in June, 2002 - but I have all the content, and can get to it any time I need to. For that matter, any of the bloggers on the site can get it from me (although, that's not as good as having access themselves, I'll admit).

Not everyone is going to solve this problem the way I have - write your server software and have access to the server itself. That does point out something that blog sites should offer (maybe they do, it's not like I've investigated much) - offer their users a way to archive their sites to local storage, or even something like S3. That way, anyone could ensure that their history doesn't disappear.