I got the DC card last year and it was worth it for me. The hopper passes as reported are a measly 5% off. But is in inconceviale to think that you go to WDW without purchasing anything. You get 10% off at Downtown Disney which is the only place I buy any shirts or souveniers. ALso, you get a discount on some restaurants, Disney Quest and the water parks if your hopper did not cover it. Last year, we used the card for Hoop De DOo Revue.
I also use it to buy merchandise in the Disney stores. Radio Disney was on tour this year and it had a performance about 15 minutes from my house. I received 4 free tickets in the mail. I know this was of course due to owning a DC card. My DD got to see Aaron Carter, A-teens, Myra and Jessica SImpson. Also, last week, I received a 50% off card in the mail to see Beauty and the Beast on Broadway. I got tkts for January. The recent news letter allows for $10 off the renewal price which if you sign up again by Dec.31st. This makes it $30 for the year. If you go to WDW once and stay inside, you certainly will recoup that $$$
For these reasons, it is worth it for me.