Of course the iPad is not solely an entertainment device. It offers serious functionality such as such as simple-to-use email and a fine e-reader for, y'know, "books." At the same time, it lacks the goods under the hood to make it a viable alternative to a true "tablet computer," for mainstream work...
Big; gorgeous screen; Works with current iPhone/iPod touch apps; Up to a 64GB of memory (and 8+ hours of battery life) in a slim package; Movies; music; internet and more; big enough to share and intuitive to operate
How are we supposed to hold it for long periods of time; Onboard sound is severely limited; No flash support; Charging is not as simple as it could be