Good question, we are exactly in the same situation and age range.
I just want to point out one thing...Depending on what country you are from, your parents would need to have a "good" English understanding even if they won the DV lottery. I think if they get the "interview" they need have the basic English at least.
In my case neither one of my parents speak English. So I've just registered myself last October 2012....
Now I start thinking it was a mistake and I should have registered my mother and father as well to increase my chances.
Another thing is, even if any of them WON, I'm not sure if I would benefit from it at all! I'm over 21yo already!
May the most knowledgeable members from this forum correct me..