Smoke smell goes away in time. I bought my car from a smoker, and that smell went away. I've bought some games from smokers, and the smell also went away.
But I guess in way, I don't really care how a game smells, or how it tastes, or what it sounds like. I do care however, what it looks like. My anxiety is all in the inevitable deterioration of all labels, and covers. The wrinkling of inserts do to poorly made plastic sleeves. The fading of colors do to UV exposure. 10 years down the road, most Wii games are going to be a nasty looking tan color. Worse than anything a smoker could do them.
Go compare the whiteness of your Wii spines, and see if some of them are less white than the others. That's what makes me panic.