Ahhh Art direction, so... the direction of art inside of a gaming company, sounds pretty simple, probably really hard!!
It was noticeable that the main link : http://www.bioware.com/bioware_info/jobs/positions/art_director.html wasn't actually working, (wells it dead) so i scouted some other links.
Anyway back to the point, merely to be considered as an art director, someone must have a minimum of 5 years experience as a technical artist or some other form of artist from the gaming community, so obviously they have to be good at what they do, as a director they have to evaluate the work from their different specified teams so production can be moved on and dead ideas can be improved upon or removed from the production process. They have to make a lot of important decisions about the work involved in their company's creation pipeline and they also have to have an understanding of the open market as a whole to see what the customer likes and wants. They themselves need to be creative and produce good pieces of artwork to inspire their artistic community, but I believe there main responsibilities are to evaluate and guide fellow employees.
I imagine there are many differences between a game art director and a film art director, but I suppose there could be many similarities as well. Game art directors have to have a large understanding of graphics programmes, as well as an understanding of other computer programmes like photoshop (I'm sure film art directors also use programs like photoshop etc) it is likely that game art directors have to have an understanding of the market and the wants of the customer, knowing this they also probably have to have understanding of environments that the customer wants to see in a game. Film art directors have to have a deeper understanding of areas and environments, they also have to have an in depth understanding of camera angles and the use of filming technologies and equipment.
Lots of skills would have to be improved to become an art director, evaluation skills would need to be improved greatly, an art directors decisions can sometimes make or break a company the right decisions have to be made to make a good computer game. Drawing and perspective work would also probably need to be damn near perfect (no surprises there with what we have to do on this course!!)