Yes, PLEASE, if you are in Disney always take your picture ID with you. I can't tell you how many guests come in to buy AP's and don't have a picture ID. Most say because they are staying in a Disney resort and take the transportation it is not needed. Well now it very much will be needed. Save yourself the trouble in case a ticket gets lost, you don't know how much is left, or you want to purchase a ticket and BRING ID! The CM is not suppose to sell AP's, and as of Jan 2, tickets without them, nor or they supposed to read tickets without asking for a picture ID. Many guests get upset with the CM's for asking, but it is for the protection of the guest and their purchase of the tickets. Children will not need an ID as long as they are accompanied by an adult with a valid picture ID. Biometrics will not be used with a child's ticket, the child's fingers grow too quickly at that age and they wouldn't match anyway. They won't have to adjust the height of the machines, however they will be adding new ones to accomodate all of those who will have the new tickets.
A good thing is everyone will be in the Disney Computer system, so like AP's now, if you loose your ticket, you will only have to take your picture ID and have it looked up to have it reprinted. No more copying the back or trying to hang on to receipts. See there is a Silver lining!