But will it replace the Netbook? I don't think so. Apple is still pursuing their closed application development model. This mean that you will not be able to load anything on it that has not been approved by Apple.
The PC industry was born on openness. I very much doubt that Apple will get that many market share with a closed model.
The iPad inherit all the bad things of the iPod Touch/iPhone... Proprietary connectors, Apple controlled market, no multitasking, etc.
I guess the only thing that's good about the device it's the starting price. 499$ for the 16G Wifi only model is not too bad. It looks fast (but what do you expect on a device running a mobile OS with a CPU that is twice as fast).
I think I'll pass and wait for a tablet, slate, whatever you call it from Palm. At least WebOS is multitasking and it's build on openness.