Nintendo's just announced an update for the series that started as a Wii pack-in. Nintendo Switch Sports will land on the Switch on the 29th of April.
Nintendo Switch Sports sees three classic sports returning - Tennis, Bowling and Chambara. You'll also be able to play three new games: Soccer (Football), which uses a giant ball, just like real soccer (football), Badminton, which will please friend of Eurogamer Ed Thorn, and Volleyball. I don't know why I capitalised all the sports but it's too late to change that now.
You can attach a Joy-Con to your leg with one of those strappy things to play Soccer's shoot-out mode at launch (strappy thing included with physical copy of the game), while a free Summer update will add the ability to play actual matches that way. A second free update in Autumn will add golf, which sounds pretty sweet. Nintendo will be doing an online playtest of the game between the 18th and 20th of February - you can take part if you've signed up to Nintendo Online.
Also, they've done something to the Miis and they look a bit weird now. Oh, and there's local play on one system, and online play against friends and randoms across all sports.