I agree 100%. The mouse is great and I don't think GUIs should drop it or anything, but it's wonderful to have the ability to keep your hands on your keyboard when doing data entry tasks and the like. I also think that when you design for both keyboard and mouse input, it will force you to consider rough edges of your UI design in a way that you wouldn't have to if you were just designing for one. So the app will be better as a result.