A couple of observations...
How can people be disappointed or criticize the iPad without actually holding it and using it first? I'll reserve judgment until then. An iPad is not simply a larger iPhone/iPod Touch, but rather the iPhone/iPod Touch are scaled down versions of the iPad concept which existed first.
The iPad is designed primarily to be a convenient and efficient way to consume digital media with productivity being secondary, although if anyone can create an intuitive and elegant multitouch UI for productivity apps, it's Apple. Up until this point, most tablet PCs have used not their own UI optimized for touch input, but rather a desktop UI (Windows) with a host of add-ons to enable touch. Not the optimal solution.
Netbooks - forget about them. They're simply cheaper PC laptops in every sense of the word "cheap". Are they better at browsing? No, it's actually a much worse experience with their lower resolution and pixel density.. They do nothing better than a laptop.
I can see getting an iPad to use around the house to read articles (digital publications - see link below), browse the web, and catch up on email. I can also see carrying it along with my iPhone instead of my 13" MacBook Pro when I travel. Much smaller, thinner, and lighter with better battery life, and it could be much better in the airport and inflight. Throw in an Apple wireless keyboard if I need to do a lot of typing. I can't tell you how many times I've tried to get by on a trip with just my iPhone, and found that it was only lacking in having such a small screen.
If you want to get a glimpse of how the iPad will be used to consume multimedia content and the future of digital publications, watch this video. They're already working on iPad versions of Sports Illustrated, Vanity Fair and Wired magazines:
Daring Fireball's John Gruber actually handled the iPad for about 20 minutes and has a good analysis here:
http://daringfireball.net/2010/01/ipad_big_picture





