OK, I'll give this one a whack...
We stayed at ASMu last June, and drove along the sidewalk of which you speak. The sidewalk basically begins at the All Star resorts, follows the road towards CSR (passing the big McDonald's along the way) and continues to Blizzard Beach.
We seldom saw anyone walking along the path, as it would be quite a hike from All Stars. It's probably not too bad from CSR. Of course, the heat would have a lot to do with how nice the walk would be. We did see a few people riding bikes on the path, as well.