I play my Wii virtually all day everyday and wish to know that when my Wii will die out (years from now), will it scratch my game discs? I've heard issues from other people that their game discs get scratched from the Wii. So will the build-up of dust and/or the Wii coming to the end of its lifespan scratch my GameCube and/or Wii discs?
No matter how much you use your Wii, it should never scratch discs; I played mine for a solid 5 years, and it didn't scratch a disk once. =) The only time the Wii will be scratching discs is when something physically breaks, which would only happen from if you accidentally hit, drop, etc. your Wii and therefore damage it.
So play to your heart's content, friend.