So, I've now seen the new Tolkien book (at the Border's, in the mall), and it looks v. good indeed. It's more substantial than I expected, at about 350 pages. In addition to the two poems (the main event), the commentary, both by CT and excerpted from various notes and lectures by JRRT himself, promises to reveal a good deal about Tolkien's ideas about the Eddas.
In the meantime, if like me you're waiting for your copy to arrive, here's an interesting interview with Christopher about the book, his father's popularity, and other related matters. Thanks to Shelly for the link; I advise clicking on the follow-up button for the full length version.