That's not going to happen anytime soon. Walmart is trying to offer service like Amazon, but they don't have their shit together enough to succeed at that level.
Recently I wanted to buy a new Roku, and the Walmart site said it was available for pickup today nearby store. Great! I can order it and pick it up on my way home. But wait, when I select it and go to checkout, the site now tells me it will be available for pickup in 5 days. WTF Walmart?!!
Their site was being stupid, so I decided to just stop at Walmart on my way home and buy it. When I get there I have to spend time to track down an employee, and they have to track down someone with keys to get it out of the glass case. Then I realize their in-store price is $10 higher than online, so I have to wait while they track down a manager. After all that bullshit, the the manager tells me they can't match the price on their own fucking website.
I took out my phone and ordered it from Amazon in front of the Walmart manager.