I finally got my hands on an iPad thanks to John. After using it for a while, I figured I'll let you guys know what I think about it. 

1. The form factor is awesome. The screen size is just big enough to enjoy reading, movies and games. Coupled with a touchscreen interface, you have an easy and fun to use device.
2. It's all about the applications. Like the iPhone and iPod Touch, the App Store is the most important feature. Thousands and thousands of applications at your finger tips. Also, the new iPad specific apps like Mail and Calendar is so much better than those in the iPhone.
3. Great for travelling. If you are looking for a device to keep you connected and entertained, this is it. It might not have all the functionality of a laptop, but you can get most things done on it. And it will probably do it better too, as long as you aren't trying to access something on a thumb drive.
4. Useful for presentations and demo. As a web developer, I can see this being used as a device to present keynotes and live demonstration of web applications. Apple released Keynote on the iPad (their Powerpoint competitor) that allows to not only view but create presentations directly on the iPad.
5. Needs to lose some weight. I find the iPad a little too heavy to hold for long periods of time. The 3G version could be even heavier. Most of the time, you'll want to rest it on the table or some other surface. A cover that can tilt the iPad is a must.
6. Getting stuff into the iPad isn't easy. You'll need to either sync through iTunes or use applications like GoodReader to transfer files to your iPad. And hopefully the reader can open it. Another way is to use Dropbox and sync files between multiple computers. The reader in Dropbox crashes often though.

Overall, it's a great device that can only gets better as more and more applications are developed for it. It's definitely not for everyone but if you are planning to get one, try it out first before taking the jump.