Yes, it has been mostly a book/author marketing model. But I agree with Shawn there's no reason it couldn't be adapted. An author client of mine has had GREAT success with it. Also, the hosts really seem to enjoy the networking and social aspect of hosting something different their blog. I like to think of it as a bit of a "win win."
I'm hoping to gather a mixed group of creative folks: puppeteers, authors, actors, creativity coaches, etc. so it could make for an interesting online gathering.
More details are available at
http://www.hupdaditty.com/blog-tour/