Nintendo has reopened its Wii U and DSi shops following a period of maintenance. This follows news that Nintendo would be closing its Wii U and 3DS eShop to offer content in other ways. Those who had previously purchased games were left without a legal means to re-download them. Nintendo has reopened the shops, allowing owners to re-download their games. Neither shop channel is offering new purchases, and support pages state that downloads will be discontinued at a future date.
From Nintendo Support: Wii Shop Channel Discontinuation
It is no longer possible to purchase new content from the Wii Shop. However, for the time being you may continue to re-download content you have purchased or transfer that content from a Wii system to a Wii U system. Be aware that these features will eventually end at a future date.
Thank you for supporting the Wii Shop Channel and for being such great fans of Nintendo.
From Nintendo Support: Nintendo DSi Shop Overview
• Previously purchased titles can still be re-downloaded on the Nintendo DSi family system. However, this option will also be discontinued at some point in the future. (Exact date TBD)