I just bought mine last month, but thus far it's had no dust accumulation...Super Mario Bros. U has been getting the most attention, but I've also been having fun playing old virtual games (Super Mario Bros 2, etc.) I didn't own a Wii prior to this, so I've been trying out some Mario games for that system. Soon enough Pikmin will be here, and then Mario 3D, Mario Kart, so although my options aren't huge at the moment, I have faith that the system will get regular use for some time.
Wastes of time for me have been Nintendoland and ZombiU, but only due to personal preference.