This could be a book-length discussion. In short, a good CIO is someone who can position IT as a business enabler rather than just a service, someone who understands/promotes the value of information security, and someone who sets goals and sees them through to their accomplishment. Having a technical background and being able to inspire his/her workers to be the best they can be are big, big plusses. You don’t see either of those all that often but when you do the person really stands out as a top-notch leader in the field.

The CIO shouldn’t be to strong in technical skill because then they spend too much time doing IT work instead of directing IT work. They need to have good people skills but need to also understand the importance of clear vision/goals, IT security, and the continuity of the products they buy and not to hobble together a system with the cheapest products they can buy. They should know enough to be able to hire the right people to do the job.

Having strong technical skills is fine as long as they have the ability to properly lead and delegate. The more the merrier to me…that way they can understand the real issues that admins, developers, and other technical team members are up against.

When I see questions like this I tend to wonder why the question is being asked…I’ll assume you have career aspirations about becomming a CIO and are currently a ways away from that goal, but want to tailor your experience to best be suited for that role when opportunity arrises.
First thought is that nobody ever is given theat kind of opportunity unless they have a wide base of IT experience. You have to come up out of the trenches doing some technical work, and to continue you climb up the career ladder you need to become an effective leader of people as well.
I don’t think it is realistic to be offered a CIO opportunity without first developing a wide range of technical experience and leadership experience.
To more specifically answer your question about which is important once you land the spot, I have to again say both. By the time you get to a CIO level, you have directors and managers below you to manage the troops, but now you are the C level person who has to socialize your initiatives and build a concensus within your peer group. The technocrat who doesn’t know how to effectively fit into the culture and politics of the people you need to garner support from is doomed. That being said, a CIO needs to have the technical background to align corporate long range plans with the properly sized technical solutions. To do this effectively a CIO needs to understand technology trends and the solutions available.
I suppose if you had to be better at one or the other, the people part may take first chair…you can always leverage the technical knowledge of staff and the network you build around yourself.