Looks like we might be getting a demo for Mario Golf: World Tour, at least for Europe. A note on the game’s official page in Europe indicates a potential demo:
Nintendo Network ID registration required to download demos from Nintendo eShop. Terms and conditions apply.
The game can also be found in a search result when looking up available demos for the 3DS. Do you think a demo will release near launch? If it’s true, do you plan on downloading the demo?