Late but in case someone missed it, online fee will be $19.99 for a year, but youi can also buy it just for a month or three.
source Nintendo NA
This was reported way back..
So far what was shown at e3 for the switch
Fire Emblem Warriors
Mario + Rabbids Kingdom Battle
Rayman Legends Definitive Edition
Steep
FIFA18
Skyrim
Rocket League (crossplay with everyone but PS-family)
Super Mario Odyssey
Xenoblade Chronicles 2
New Kirby game
New Yoshi game
Metroid Prime 4 in works
Pokemon RPG game in works
Some game from GungHo in works