My wireless Internet has never been down since i've used it. My telephone land line has never been down either. We have numerous power outages from overhead lines getting knocked out from trees mostly, some ice and rarely vehicles hitting poles. Longest without power, just over two weeks, long enough for cell towers to go down too.
That said, if someone comes to me and says they want to put some sort of networked gear someplace, they usually want to use wireless, i ask them how reliable do you want it to be, and they almost always say, very reliable, it can't go down. I tell'em, they got to pay for a hard connection then, not wireless.
