Learning a bit about CAD production will help, but you want to check in with yourself from time to time to make sure that you're doing what you want. Getting out of the trenches can be a struggle once you're in a firm's production machine.
It's fairly common for a small-med sized firm to hire on a 3d guru that also knows some CAD. That way they can minimize their risk of potential overhead while there is no billable 3D work. Gotta be careful here. You could end up in a lose-lose situation. If you prove to be a good worker on the boards, project managers will try to hold on to you for every project and you'll never get a chance to develop your 3D skills. You're also likely to find yourself surrounded by other CAD vets that have been aching for a change of pace and see themselves as the one who should be doing all the fun 3D work.
My advice...
Soak up as much practical production experience in school. Work as an intern somewhere to see how the system works. Teach yourself everything you can on 3D. Get a few killer images together and re-apply as a resident 3D guru, but never mention a THING about knowing CAD.
If you'd rather go straight into 3D, find a place that already has one or two 3D folks in-house and work as their support. You'll get better faster and bypass a lot of the politics. You'll learn what you need from the drafting side and when your dept head decides to start their own company, you can choose between going with them or taking over.
I'm starting to sound too preachy, so I'll just add one more general bit of advice to anyone just starting out. Visualize, visualize, visualize. Not 3D or anything, but in your career. I know it sounds corny and you've probably heard it before, but it's easy to become paralyzed with the unknown. Taking that next step is frightening for even the most confident professionals. The more you see yourself over and over doing what you want, the more focused you'll become in making decisions. Even the subconscious ones. Oh GOD, I sound like Tony Robbins or something.
You'll do fine. Posting this thread shows that you're serious about each step of the way. Be sure to keep us informed.