I have scientific proof that it does indeed shorten the lifespan of the Wii. You see, the first Wii I got was on launch day. I stayed in line for well over 45 minutes to get it. That was some of the hardest work I've ever had to do. Anyway, it started breaking down after about 3 years with moderate play, maybe 2-3 sessions a week. I did not mod it, since I was only 6 at the time.
Then, I had saved up enough from my Mom's secret money stash, in the vinegar box in the bathroom (what's she do with vinegar in there anyhow??
). For my birthday, she got me a new yo-yo with Dora the Explorer on it. I traded that to Rico down the street for his Wii. He said his Dad couldn't find where to plug the controller in, so it musta been broken.
Anyhow, I gave it all my stash cash over to Ahmed at the 7-11. He said he had a friend at his church that was good with those smoldering irons. I got this Wii back just in time for Christmas. Then, my sister, Jill, has her birthday in April. The folks give her her own Wii remote and nunchuk, with a Wario's Warez game. I tell her she best find her own Wii, 'cuz mine is private property. Of course, she runs and tells on me, so now I'm expected to let her use my hard-earned Wii. I say, "That's whack" and my Mom flips out. To make a long story short, she grounds me from my own property for a month! My sister is all up in my face about her game. She gets a jar of honey for her biscuits and heads to my room. I go outside to call on my bff Rod, so we can fry some ants with his grandpa's magnifying glass. Next thing I hear, my sister is crying like the baby she is. No one showed her how to work a Wii, so she ate the game disc and put the honey-soaked biscuit in the Wii. Now, letmetellyousomethin, I don't need to say what happened next, but I will anyways. Right at that moment, the modchip makes a noise that sounded a bit like, "Yummmmmpft." And that Wii was broken, totally.
I won't bore you with what happened to my next modded Wii, but it only lasted 6.3 months before the modchip went after the mailman, and got maced right on the Vcc line!! It was not a pretty sight.