MacBook > iPad
Contrary to popular belief, an iPad is not the best device for a flight. I just flew from Los Angeles to Albuquerque to San Francisco and back to Los Angeles and developed a this blog from scratch on my MacBook. How could I ever expect to do that with an iPad? Sure, I could hook up a keyboard and write some code. But with my MacBook I'm able to have an Apache server with PHP on my local computer and develop, debug and view what I'm doing in real-time. Now everyone is not a web developer, but most people could get something done on a flight instead of watching a movie. Sure, the ipad can be used to read books, but I think a Kindle or Nook is better for that.
There are 2 classes of devices: ones that fit in your pocket and ones that fit in your bag. The iPhone/iPod are fit in your pocket devices, and people bring those everywhere they go. Larger devices must be carried in a bag and therefore are only available when you plan to need them. This puts the iPad in the same catergory as a MacBook.
The only reason to get an iPad is if you want something with a Mac-like experiance but do not want to fork over $1000 for a MacBook. But really, the functionality and lifespan of a MacBook makes it worth the extra cash. Apple sees the iPad as a iPhone-type device that will be replaced every 2 years while their compters last 3 to 5 years.
Everyone who wants an iPad: just get a MacBook and you'll be much happier.
Also, the Apple spelling dictionary contains iPhone and iPod, but not iPad?