In addition to the shop at DTD and Universal CityWalk, there are a couple of locations in the town of Celebration (10 minutes from WDW) where you can buy cigars. One is the barber shop on Bloom Street, facing the lake. Another is the cuban restaurant, Columbia, on Front Street, also lakeside.
If you want a fabulous cigar store, bigger than any of those mentioned, go to Corona Cigars in Dr. Phillips. This is on Sand Lake Road West (west side of I4). Either take I4 east to exit 74A, turn left, and it's about 1.5 miles down on your left side (in the same shopping center as Barnes & Noble, you can't miss it). Or an easier, and much more pleasant drive is to take 435 north (Vineland Road) to Sand Lake Road and make a right turn, it will be about half a mile down on your right side. You can pick up this road just outside of DTD around the Crossroads shopping area. Corona Cigars has a website with detailed driving directions, so your best bet is to check them out because mine might be a little sketchy and not precise enough.
But this is an incredible cigar shop which also has a small bar and shouldn't be missed if you are a real cigar afficiando.
Susan