The Tablet Ecosystem
If you're thinking of this as a device you're going to be spending a lot of time with, perhaps the most important consideration is whether it's part of an ecosystem.
When you buy an iPad, you're pretty much tied to Apple's iTunes and Apps Stores. There are also tens of thousands of apps available in the Android marketplace, while selections for BlackBerry and HP's WebOs are limited. One note on the RIM PlayBook: To use email, you need to have a BlackBerry smartphone. The PlayBook does not come with its own email application, so without a BlackBerry you'd need an Internet-based email like Google's Gmail.
The tablet is the new hot genre, and for good reason. You can use it to accomplish almost anything you can on either your smartphone or your computer, with two notable exceptions: despite the ability to do voice over Internet (VOIP), it's not likely to replace your phone. And for many people the virtual on-screen keyboards just can't substitute for the real thing. But if you're hitting the road, want to take your music, your travel guidebooks, your novels and your movies with you, you might want to remember that old American Express commercial: Don't leave home without it.