Nintendo has released a list of games and services that will be affected here.
Users will still play the games in offline mode.
Nintendo added that online play for Wii U and Nintendo 3DS games would be unaffected (aside from the Wii mode on Wii U and Nintendo DS games on Nintendo 3DS family systems). Other online functionality, such as access to the Wii Shop Channel, the Nintendo DSi Shop and video-on-demand services, will also not affected, at least for now.
"We at Nintendo sincerely thank our fans for their continued support of our company's legacy systems. Your enthusiasm for games made for these systems speaks to their longevity, and the passion of Nintendo fan," Nintendo said in a statement.