I think that's the best way to go with things as well. The history of any character that has DF origins isn't really needed. Though this does feature a few character from the old books, this, we're hoping, will be a fresh start for everyone involved. While DF characters would have established relationships with other DF characters, it doesn't stand to reason that everyone else would know about their history.
The actual story thread will likely be started sometime this weekend. Like I said, the only plot that will be there is whatever one happens to develop as the people posting get their bearings and start to get a feel for each other. It's not going to be something planned out put into motion, whatever happens will just evolve according to what people post.