According to this Reuters article, Wal-Mart plans to open as many as 400 in-store health clinics. One fact that makes it sound a little better is that the clinics will not be managed by Wal-Mart, but by local hospitals. So I guess it is the same, in principle, as having a McDonalds, Subway, or Midwest Bank operating in the store.
It seems to me that Wal-mart is trying to create a little city of commerce within its stores. However, I doubt we will see something like a public library operating inside a Wal-Mart since that would compete with book sales. But maybe soon they will open an exercise facility, movie theater, and who-knows-what-else.