As in other recent threads about this same topic, it seems that Disney is falling behind in sending out the CC cards to people. Once you sail on
DCL you automatically become a member. You might want to call them and get your CC number. Keep it handy because when you call to book your next cruise, give them the CC number and you will received a free gift in your room (beach towel, link below) and some CC club pins. You will also be invited to a CC reception on board with the Captain and staff. They serve appetizers and free drinks.
When you get to the port there is a dedicated CC check in line, though I have found it to be longer than the regular line. You get no special benefit to checking in on that line so just find the shortest line and get on that.
There is also a toll free number to call book your next cruise for CC members. The number is 800-449-3380. You used to get a onboard credit, but they have done away with that. They have also done away with sending the Disney Insider Magazine.
Here is a link to the current CC gift.
http://community.webshots.com/photo/50699182/50699254MYmhzE
MJ