I'm getting it first week, but I never preorder. I mean, I walk into the store on the launch day for NSMBWii and Brawl and picked up a copy. Release week for NMH, MKWii, and SMG. I think most Wii gamers don't ever preorder. The game will do fine.
"Now, a fun game should always be easy to understand - you should be able to take one look at it and know what you have to do straight away. It should be so well constructed that you can tell at a glance what your goal is and, even if you don’t succeed, you’ll blame yourself rather than the game. Moreover, the people standing around watching the game have also got to be able to enjoy it." - Shiggy