We finally have information in regards to the online service that Nintendo has said since their presentation of the Switch. It is not officially called : Nintendo Switch Online.
First, it is slated to be released next year in 2018. But before then, you are able to use the service so as long you have signed in with your Nintendo Account. It’s states as follows:
You’ll be able to play compatible co-op and competitive games online by signing in with your Nintendo Account. Online play will be free for Nintendo Account holders until our paid online service launches in 2018.
After the free-trial period, most games will require a paid online service subscription from Nintendo in order to play online.
This service is only for Nintendo Switch. It does not affect online play or features for the Wii U or Nintendo 3DS family of systems.
They also mention in regards to the Nintendo App that would allow players to set up voice chat and play appointments with their friends. I presume this is similar in regards to Discord. This app will be available for download in Summer 2017. Also to not be out done, subscribers are able to download classic titles to go, such as Super Mario 3, Balloon Fight , or Doctor Mario. Further details are yet to be announced if we are able to keep these titles, like with PS Plus. This also includes deals and offers.
Lastly the price:
1 month: $4
3 months :$8
12 months(year): $20
The price is in great competition with the other online services of PS Plus and Xbox Live. Whether it great in value is still remain to be seen. Overall, it still great to hear information of there service. They laid out a chart in regards to what you gain in this subscription, which you can see on their information site.
Further details will be provided as months goes on and as we head into E3. Check Nintendo for more information.