More than once in forums when people have posted to essentially say: "I am really interested in learning Wing Chun. But the nearest instructor is X hours away from me" I have advised them to contact that instructor to find out what lineage he or she is in. Then find out if anyone in the lineage has released instructional DVDs. Or ask the instructor which DVD series they would recommend. Then find a partner and started working from the DVDs. Then visit that instructor as often as your budget and schedule allows to get direct instruction, feedback, and correction. No, this is not the optimal way to learn. But with a little bit of physical talent as well as some persistent hard work it is very workable. Invest in a video camera and get the instructor's permission to film lessons or feedback when you visit him.
Now, if you are already learning or have learned Wing Chun and have a good grasp of the basic structure and mechanics, you can watch other people's DVD series and learn a lot. You can pick up on different interpretations or applications of techniques. You can learn a different approach or deeper understanding of some of the concepts. You might even pick up on good things that you missed in class because you weren't there or they simply weren't taught.
Most people that can learn well in an actual class can also learn well from watching a DVD. Its a matter of being able to think in 3 dimensions and take something you see visually and do it physically. You might be seeing the instructor standing in front of you in a group class or you might be seeing an instructor in front of you on the TV screen. The benefit of the live instructor over the TV screen is that he can say..."Hey you! You're doing that wrong! Do it this way!"

So you have to have the ability to pay close attention to the movement, watch yourself in a mirror, and self-correct. Otherwise you can learn a lot from DVDs!