I think you would have to have both, but if I had to choose one, I would say it would be vision. Vision will allow you to move a project forward and see many possibilities. Innovation is also important, but is not always persuasive.
i think if you have vision... it is followed by innovative mind....
I would say more a larger understanding. So it will be the vision. The innovative approach is more a part of the profession: we always provide new solutions for our clients needs. The design itself is a problem solving challenge and continuing to find solutions for needs expressed always in new ways is making the architect to be innovative. I am not talking about new forms, new aesthetics, but the novelty of each project demanding new answers.
I think that vision and innovation go hand in hand. Architects are considered generalists who know something about everything rather than everything about something. The more adept we are at being a generalist, the better we are at assessing multiple factors (be they social, political, environmental, technological...) and creating a vision of a viable design concept. If you have confidence in your ideas you will find a way to make them work.