While at Tech-Ed, I picked up some literature on the efforts of Novell and Microsoft to build bridges with each other toward interoperability. I found that they also have a web site on this topic where you can still read the original press releases and FAQs from November 2006. Conspiracy theories aside, interoperability is probably a good thing.
While I was looking for more info on their planned directory & identity interoperability, I came across an article titled Novell eDirectory vs. Microsoft Active Directory. I can assure you that it's not part of the interoperability literature. In fact, I wouldn't be surprised if it's soon taken off line to preserve the recently positive flow of energy between these two companies. While it's clearly and unapologetically written to sway would-be buyers toward Novell's directory product, it's quite an interesting read for those evaluating LDAP options. If you read my introduction to LDAP directories and are ready for a more thorough drill-down that doesn't require you to read the LDAP RFC, it's a good next step. Novell provides a thorough business level view of what to look for in a directory server.
Incidentally, I didn't find much on their plans for directory interoperability. From what I could find, it sounds like any identity interoperability will initially be at the user access layer and not at the data storage layer. If you have any more details, please comment!