Bear in mind that this is not yet the real deal, the dual-core Tegra 2 chipset is not fully utilized yet (in fact, the current version of the QNX OS on the tablet only uses one core at the moment), so there's still a fair bit of coding to be done. The coolest feature for us - the whole bezel around the 7" screen is touch-enabled, and can be used for navigating around the interface, and interacting with applications. The bummer - no dedicated PIN for BBM can be used on the PlayBook, you will have to make do with pairing up your existing RIM device to the tablet for actual BlackBerry-ing.
With that out of the way, everything looks incredibly smooth, and the lag here and there can be easily attributed to the prototype nature of the examined device. The "views" concept from BlackBerry 6 is also here, easing navigation, so clearly there is a trend towards converging all RIM's devices into using one and the same mobile OS down the road. Multitasking is also top-notch, see for yourself in the video below.