UPDATE: Walmart's site is now displaying this error. Please understand. The SNES Mini was on sale for a whopping 25 minutes before this happened. We can assume that they are sold out or their site collapsed underneath the stampeding heard of Nintendo fans.
Super Nintendo Classic is available for pre-order at Walmart. This is not a drill. We repeat. This is not a drill.
Here is the link again. SNES Classic Pre-Order at Walmart.com.