Though this may make the game too similar to Civilisation and others, I would love to see an intellectual/scientific side to the dwarven life. It seems strange that a bunch of pilgrims with (depending on how you set it up) no knowledge of siege weaponry and mechanics can, in the space of two years, learn how to design, build and maintain a ballista. I would love to see a research element added to the game someday so that dwarves can only produce things that have been researched and learned about. Hence dwarven skills would be proportional to this research level, and skill couldn't exceed skill understanding -too greatly- (it still COULD, but there would need to be a soft cap on it, as a new skill/product/service often needs the masterful people for it to be used properly).
On the other side of this would be a new Training skill so that legendary dwarves could train newbies. Hence being legendary doesn't make them a good trainer and vice versa, but a good trainer can more efficiently transfer research knowledge to those who are using the skills.
Of course, my ideal fortress has libraries and research labs!(which adds the whole element of stone tablet/paper & ink production!). Then knowledge could be the new tradable commodity!
People have also talked about Nobles adding some sort of skill management/training function. This would work in beautifully, and, with enough research done and the arrival of the new scientist-education specialist, would justify the unlocked access to such a screen.
[ June 17, 2007: Message edited by: Faces of Mu ]