Michael,
The PrepCast is valid both for the PMP Exam and the CAPM Exam even though it was created with the PMP in mind.
I recommend to my CAPM students that the simplest way to prepare for the CAPM Exam is to read the PMBOK Guide several times (after all, CAPM is mostly memorization) and as you read the PMBOK Guide you can go ahead and watch the corresponding video lessons of The PrepCast to help solidify the concepts.
I've even had a number of people who just watched the PrepCast and passed the exam. But frankly - I discourage that strongly. I want you to understand the concepts in their completeness.