It's worth it if you follow the program.
I've been attending meetings since July 16th of last year and have lost almost 45 pounds. I've gone from an 18W to a size 8. I love my meetings and find them very motivating and a good accountability method. I have the monthly pass ($39.95) that lets me go to as many meetings a week as I want and access to E-tools on the WW site.
On the other hand, the 2 friends that got me interested in going have both dropped out and have gained weight instead of losing.
I am 8.4 pounds from my goal weight and once I make lifetime (free meetings then) I hope to work for WW as a receptionist. I figure that will help keep me motivated to keep up with the healthy lifestyle I've learned.
So yes, I think WW is very worth the money I've paid. I've gone from being a very unhealthy 41 year-old to having so much more energy. I really like Weight Watchers and feel it's been worth every penny.