170K Japan and UK combined.
I say 300K for the Americas and 100K for Europe (because of France). That makes for a grand total of 570K by the end of May, just retail. Quite good if you ask me, when compared to other Wii U games.
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.