I haven't been to the one on Poinciana but the new WalMart on 27 is absolutely huge. It's so big that I wouldn't be surprised if Disney included it as one of the extras on a Hopper Plus pass. I think it will take longer to walk around WalMart than it does to walk around Epcot.

It's dead easy to find. Just take the 27 north. Go past the junction with 192 and then it's on the right at the next set of lights.