Yep. Anyone flying into MCO can use it. You have to call Disney and make a reservation. They will need your flight numbers, date of arrival, date of departure, the resort you are staying in and the number of people in your party. Then, at some point, they will send you a booklet with instructions and your luggage tags. Hopefully, you will get them 2 weeks or more before you travel. You put the tags on all your checked luggage, it gets pulled out as soon as you get to MCO and put on a truck. You check in at the DME desk and hop on the bus.
Now, for your return....if you are flying SW you check out of your resort as usual. Leave your bags with bell services if you are eating/going to a park. When it is time to catch the bus, about 2 1/2 hrs. before flight time, you come back, get your bags and stow them under the bus and you hop on and go to MCO. If you are using a 'participating' airline the difference is..you can check-in for your flight at your resort. You will get your boarding passes, your luggage will then go directly to the airport and put on the plane. You eat/go to a park..whatever. When it is time to leave, you come back to the resort, hop on the bus (same as the 'non-participating' people are on!!) go to MCO and amble on down to the security area...no stopping at the check-in area.