eShop is still undergoing maintenance.
Part of the new 3DS system update is live, as 3DS owners around the world can download the substantial addition that adds Find Mii 2, Accomplishments, and more to the StreetPass Mii Plaza, and 3D video recording to the Photo Channel.
However, the eShop, which is slated to receive several updates including demos and DLC as well as the ability to save your credit card information, is still undergoing maintenance. It is likely that the eShop will come back when the week's normal slate of new releases goes live. So, tomorrow in Japan, and Thursday in North America and Europe.
UPDATE: Apparently the European store is up right now.
Watch the video below to see some of the new StreetPass features.