A navigation and menu manager is probably one of our most requested features. It's certainly something we've wanted to implement for ages, but we have been held back by the sheer scale of the feature and how much code would be altered to accommodate it, but XenForo 2.0 is the perfect opportunity to look at features like this. If we had implemented something like this for 1.4, there would have been an extensive list of serious backwards compatibility breaks and a lot of what would be done (by add-on developers and end users) likely would have been broken by further changes when 2.0 rolls around. While backwards compatibility issues like this have happened before, we have endeavoured to keep them to a minimum in x.X-level releases.