I posted this in the "Which model will you buy" poll, but as it's directly relevant to this conversation, I'm putting it here too.
I ordered the 64GB WiFi only model. I have a great Nokia phone that runs an app called Joikuspot which turns my phone into a WiFi hotspot anywhere in the world, so no need to buy any additional 3G coverage.
I'm mostly going to use the iPad for traveling, which I do quite a lot of. I'm not sure I'll ever use it at home, but it looks to be perfect for airports, airplanes and hotels. I need to carry my work laptop regardless, as it has encrypted data and tools that won't work on a tablet or netbook, so for me the iPad is purely an entertainment device. I ordered the largest memory model as I'll be replacing my Archos 80GB PMP for watching movies (I can't wait for the larger screen!) and my Kindle for eBooks, as well as my iPod for music and Audible books. In addition, I'll use it for personal web browsing, playing games, and amusing myself with apps like GateGuru, even though it's limited to US airports.
United now has WiFi on their transcontinental flights, and while it's slow, it would be nice to do a quick email check, surf a bit, or even IM between movies without having to haul out the laptop and wait for it to boot up. Besides, even in business class there's not much room for a laptop and a snack on the tray table.