I've found the discussion in this thread very interesting and food for thought.

It seems to me that John Clements suggestion that the 'previous/next' & 'back/forward' should all be available options in the link-to drop-down makes much sense to me. I believe as a tool it should be as flexible as possible. Offering the designer choice is a good thing.

In support of having the additional options included in a future version I offer the following scenario: When designing a web site it is entirely plausible that you could include a page that is linked from several others. Once visited, the navigation should really go "back" and not to a sequential next or previous.

While I can agree Covoxer's argument that back & forward are typically browser functions, I still think the tool should provide flexibility (without needing script skills).

Regards, Ross