User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-15860919-20130922030700/@comment-5593616-20130922121843

I don't think the Norse series will be in the same world; it would be too much for RR to handle. A major crossover would have too many things happening at the same time.

Also, I'm pretty sure the Norse series will have its own wiki, unless we like change this one into a "Rick Riordan Wiki," lol.