There are still some products that you just have to see in person in order to buy. Furniture is a great example. Clothes are another example. I want my kids to try on clothes so that I know they fit before they buy them. Also, grocery is important for Wal Mart. They will always still have some kind of market.
I don't really think that Walmart is losing any customers to online shopping. I am not sure where this data comes from but I think it is wrong. Walmart has a vibrant online website. I, myself, have used it many times. I think that it is a very popular website and that Walmart will have no trouble surviving.
Walmart will survive even if they are losing their customers to online shopping. Yes, many customers choose online shopping for electronics and house wares due to the convenience and door to door shipping, but Walmart will never lose in store customers due to their grocery section and low prices. Customers would rather drive 30 minutes to a Walmart for inexpensive groceries than pay a higher price at a store 5 minutes away.
It might even be too late for Walmart. People have a lot of issues with them. They don't pay their employees well, they have horrible foreign relations, they have terrible quality of products most of the time, and their stores are generally packed with maybe one or two cashiers. They have a lot of changes to make.