This can only be a good thing in the long run if they replace it with something good. A consistent global brand that offers rewards commensurate with the money spent to get the stars/coins/points, and more consistent rewards worldwide instead of amazingly cool stuff for Japan and the dregs elsewhere.
Club Nintendo came online in different regions at different times, and was based on legacy services in some areas. The UK/Europe website is a mess, and is completely off brand: it's all stupid lifestyle photos of attractive models in white spaces which Nintendo were using to market Wii in 2007. Registering games is a struggle as you tell it each and every time what age you are and your gaming experience - maybe some European data protection law prevents them from storing your basic details, but that doesn't make it any less irritating. The survey questions are repetitive and don't even cover all the options: it always asks you whether the game you just bought was why you got the system and the options are something like "I bought the 3DS to play this", "I already had the 3DS", or "The game didn't affect my decision to buy a 3DS". These options barely make sense and don't cover the most likely scenario that you already had the system and of course this game didn't affect your purchasing decision for hardware because you bought the hardware before the game was even fucking announced.
Also, they now have a chance to properly integrate the whole thing into their console system software if they design it that way from scratch. Club Nintendo ID and Nintendo Network ID being separate is a clusterfuck and confusing to new consumers. The new service needs to simply operate based on NNID, and could even be integrated with Miiverse, or at least get its own system app on 3DS and Wii U. You could do the digital surveys right on the console.
More pie-in-the-sky but: the whole Wii U Premium thing was interesting but it wasn't that clear to me even as a follower of Nintendo where it was available and how to get it. If they follow the PS Plus lead and relaunch the rewards stuff as part of a subscription service - maybe even with Virtual Console becoming a monthly sub? That would be very interesting.