So you can sync it with your email accounts. You can also wirelessly connect with your BlackBerry to gain real time access to its contents and also use it as a 3G modem.
One possibly killer feature is compatibility with Android 23 (Gingerbread) apps. Developers will have to resubmit them to BlackBerry App World as the PlayBook can't access Android Market, but it does potentially seem to solve, at a stroke, the app-Iack issue currently plaguing Windows Phone 7 and, to an extent, BlackBerrys themselves. Continuing the theme of innovation there's to be a 4G-ready PlayBook, too, though we don't know when that will work here.
With the tablet market filling up and Apple utterly rampant, it takes a very strong product to issue a real challenge. In hardware terms, at least, RIM's PlayBook has what it takes.