I put the first "mainstream" blog into my feedreader this morning.
It's called Blogspotting and its from Heather Green and Stephen Baker at BusinessWeek.
I've known Heather since 1995 and I've always enjoyed reading her stuff.
I expect this will be the first of many. And, as John Battelle says, if they host the most interesting conversations, then they'll be a great addition to the blog world.