Dr. Yang's new "Yang Tai Chi for Beginners" DVD is very different from his previous tai chi programs. This 5-hour program was filmed in high definition at his new home in California at the YMAA Retreat Center and in the nearby redwood forest. This video is very much like having a one-on-one private class with Master Yang. It contains step-by-step instruction of the complete long Yang-style tai chi form in detail, explaining the exact position of the hands and feet for each movement. It includes solo demonstration of the form by Master Yang in the early morning in front of a mist-filled valley, and group demonstration by Dr. Yang and his CA students. It also includes a rear-view of the form that is easy to follow along with once you have learned the form, and Master Yang's commentary on some classical Tai Chi poetry.
The older Tai Chi Chuan Classical Yang Style video is a demonstration-only overview of the basic concepts of Tai Chi. It begins with Dr. Yang explaining the relationship between Taiji Philosophy and the martial art of Tai Chi Chuan. It contains demonstrations by Master Yang of the 13 Basic Patterns, the stationary and moving Taiji Qigong form, and the complete Yang style form without detailed verbal instruction. So this one is meant to be an overview of the whole art, whereas the other just focuses on the form itself.
Personally, to learn the form Id get "Yang Tai Chi for Beginners".