No they will happily charge most of you to rebuy games you already have, not me not this time. If there is one thing I learned buying Nintendo this gen it's KEEP EVERYTHING, the number 1 reason I bought a Wii U was I know it will be damn collectible in 15 years and if its the only way to hold onto my very large Wii Virtual Console library without having to re-buy the same games again I will do it just to spite Nintendo. I would happily pay a small conversion fee or transfer fee, small as in a 1 time $10 fee or less. I will NOT be paying more than that. Or I would consider a $1 fee per game but not what they did with Wii U I want everything I bought on Wii, I have 60+ Wii VC titles, I barely have 20 Wii U VC titles, mostly just DS and Wii stuff with the main SNES stuff just for easier access.
Actually I am not sold on NX yet, but I doubt it will be Wii U fail I am predicting closer to N64 levels of successful but GC levels of support. Maybe slightly higher. Depends on what great new gimmick they come up with and price.
I know they won't or there is a good chance they won't but it's the number 1 deal breaker for me. There might not be a way to do a "Wii Mode" but I am sure they can figure out a way to access the Wii store.