BobbyRach did you book your WDW accom through
DCL?
The credit card sized card does all that Melb5 says (and I'd picked up from the DCL section that it even becomes as your stateroom key on the ship) but for some reason our DCL booked resort key / charge cards couldn't have park tickets incorporated, so we got a second set for that from the concierge in the morning.
(No real drama) but we ended up with 4 sets of cards as the Dream's
were separate, DCL logo and we got
another set of blue ones for our post cruise resort.