Hopefully it's backwards compatible with the Wii U, it has the Virtual Console ready from the beginning and the account thing it's solved by the release of the system.
I probably buy it at launch, especially if Pikmin 4 comes shortly afterwards.
My bet with The_Liquid_Laser: I think the Switch won't surpass the PS2 as the best selling system of all time. If it does, I'll play a game of a list that The_Liquid_Laser will provide, I will have to play it for 50 hours or complete it, whatever comes first.