I got an error message when I tried to go onto the store today. The error message I got was :
Error Code: 005-4800 Nintendo eShop
An error occurred while attempting to connect to the Nintendo eShop. Power off your system and try again.
If you continue to experience problems, please call 1-800-255-3700 for assistance.
I called Nintendo. They say it would be back up 4pm PST. Apparently they are doing an update to the store.