I guess I just don't see any advantage to using the mouse. I mean, I look at those goblin camp demos, and just see someone with a system that forces me to hunt through a context menu every time when it's so much easier to just mash "bCwkkkkk7774" than to try to find the proper spots on the screen to click.
A first person game would have obvious use for a mouse - that has analogue look and movement style. Having an analogue input makes it much easier to interact with the game. The big push in this, however, seems to be to add click-and-drag to map viewing...
I mean, really, you want click-and-drag?! Why would you ever want click-and-drag scrolling when you have keypress scrolling already? Click-and-drag scrolling is the bane of ease of control, especially in any game that might possibly have lag, where it still thinks you're holding down the mouse button while you're flicking the mouse back up to grab again, and it sends your screen flying in the opposite direction you want it to. And you know this is going to be a problem with Dwarf Fortress, don't even kid yourselves.
A sensible all-keyboard interface is the ideal in a setup like DF has. Let's just work on getting a revised set of keys and menus that gives the player a more streamlined and intuitive set of controls, rather than gluing in some of the worst interface aspects from the rest of computing.