You will hear it all. I believe there's some truth to it but I do what I feel is best for my children. Yes, all my children (4, 3, 1 y/o) watch television but it is limited and controlled. I do use educational DVD's because I feel they can help reinforce what I am teaching my children. Remember everyone learns differently. Some learn by seeing, doing, and/or listening.
My oldest daughter learned her ABC's mostly by watching the DVDs along with the use of flashcards, and workbooks. My middle child, she's a different type of learner. I have played these DVD's numerous times and there isn't anything I can do or say to keep her seated long enough to watch the DVD from beginning to end. I still play them everyday. My 1 y/o (20 months) will sit and watch the DVD's! He can identify some of the letters in random order.
I have many different educational DVD's such Baby Genius, Brainy Baby, Your Baby Can Read, Baby Einstein, Preschool Prep, etc. My favorite set of DVD's are Preschool Prep. They use sight-recognition techniques to help kids aged 9 months to 7 years understand concepts such as colors, shapes, numbers, letters, letter sounds, sight words and much more. I've never used their workbooks but they have many books and flashcards to help reinforce what's on the DVD's.
From time to time you can find the DVD's on sale at Groupon.com They're currently on sale now
*In case you're wondering why start at 9 months it's because that's when you're child's vision is fully developed and it's when they begin to understand the world around them. This is the best time to start teaching your child!
To learn more about what type of learner is your child please click on the link.