First of all, be careful what you wish for. Do you really want to sit in this CIO’s chair? Some people think they do, but when you show them what it's really about, they want to change their mind. I've seen that happen quite a lot. I've had some people fixate on it, and when I expose them to what the CIOs job is, they say “Oh! Well, I don't want to do that.” So, I would say to the CIOs or those people who want to be CIOs, talk to your CIO and get them to share/spend time with you. See if you can go chat with them, or get them to share a typical day-in-the-life-of so you get some real insight into what the job is. It may not be the sweet spot of what you enjoy doing. The CIO's job these days is less being the 'hands-on tech gal' and more being the facilitator of decisions, managing relationships, negotiating, making trade-offs, and only after that do you get back to spending time on the technology floor. While that's what we enjoy doing, not many spend quite as much time on it as we'd like. So, if you've already got that balance between the amount of hands-on tech you're doing, the people you're leading, the technical choices you're making versus the number of people you have to influence, and persuade, you're probably in a good spot already.
I think as the CIO role has evolved over time, where the CIOs probably a generation before me all came up through the technical aspect, I came up as an IT generalist. Through project management I had to learn how to communicate with the business, especially from a business requirements perspective, and be able to communicate them in very no nonsense ways outside of tech speak or what have you. I think that has served me extremely well, in terms of being able to straddle both the IT side and the business. My undergraduate degree is business administration. I probably took a grand total of two computer courses my entire life, coming up both through high school and college, because I was actually more focused on business.