Nintendo Wi-Fi Connection, the online functionality on Nintendo Wii and DS, has been discontinued today. That will mean online modes, matchmaking, and leaderboards for several of those games are no longer accessible, though Nintendo notes that Wii U and 3Ds games have been unaffected.
A list of affected games is available on Nintendo's site. This will impact the sharing functionality in games like WarioWare DIY, downloadable content updates in the Professor Layton games, and online sharing functionality in Pokemon games. On Wii, it notably impacts online play in Smash Bros Brawl, Mario Kart Wii, and Animal Crossing: City Folk. None of those franchises have received newer versions on Wii U, though Mario Kart's is just around the corner.
"We at Nintendo sincerely thank our fans for their continued support of our company’s legacy systems," reads a statement from the company. "Your enthusiasm for games made for these systems speaks to their longevity and the passion of Nintendo fans."