Newly released gadgets with problems are nothing new, and while they get a lot of attention online if you analyze the situation you find such problems are just a numbers game.
The knee-jerk reaction to a new product with a problem like the Wi-Fi iPad is "how did Apple let this get out?" That's a natural stance for an expensive new device. If all new iPads had the Wi-Fi issue then the question would be legitimate, but most owners I spoke with are not having any problems (nor am I).
Sophisticated gadgets are the result of complex manufacturing processes, and the reality is a small percentage of any new product produced will have problems. It is impossible to build a lot of complicated products without some getting through that fail to meet specs.
Apple has probably sold at least five million iPads since the launch, so if only a tenth of one percent of those had problems that's still a healthy number of defective units. Odds are a few owners of those thousands of defective new iPads would take to the online forums to complain and see if others were experiencing the same problem. Even with some chiming in that their iPads are OK, the hundreds of owners discussing their problematic iPads would be enough to get everyone's attention.
Hopefully Apple will step up and take care of those with defective iPads. According to reports that is already happening, so in the end everyone should end up happy. This type of problem is in the end a numbers game, and unavoidable.
This is not unique to the iPad, every single gadget in production has a failure rate. Some we hear about, others we don't. The higher the sales of a new device, the more failures hit the airwaves.