There are two parts to this. At Port Canaveral, DVC has a little station where they are handing out lanyards and want you to stop by to pick one up. Then once on the ship there is the Member Celebration, it was from 2:30-3:30 on embarkation day on the Dream last week. They tell you to arrive a bit early for the character M&G. They do have you scan your KTTW card when you come in to make sure you're on their list (they used to just do this by hand using pen and paper).
I have noticed in the past 2 years that this has become more of a "game" where they split up the two sides of the room to compete against each other - of course it always ends in a tie. It's no longer the celebration of the members that it was in the past. I'm not sure how many more of these I will make an effort to go to. There are fewer raffle prizes and less getting to know the other members in attendance. Plus they seem to not acknowledge you as much as a member unless you're wearing your DVC lanyard or hat to advertise for them. After a few cruises wearing the DVC lanyard I've decided I prefer to wear my
Castaway Club lanyard b/c it seems to elicit a better response from crew members because they know I've sailed before and gives them a conversation starter.