I was highly anticipating this Microsoft since Intel's announcement of skylake. It's like the messiah of processors so there was a big question if MS could time the launch of new surface devices with mobile skylake processor mass production. And they did. Personally, I'm more interested in the surface pro 4 as the surface book is a bit too much for my tastes. Surface Pro 4 - more mainstream high end tablet/laptop market - 12.3 inches 2736×1824 resolution - 9hr battery - new bluetooth pen docks to the device via magnet now Surface Book - pretty much a macbook pro contender - 13.5 inches 3000x2000 resolution - 12hr battery (with keyboard docked, 3hrs without) - has dedicated nvidia gpu option MS is using a hybrid liquid/fan cooling solution for the i5/i7 surface pro's and i assume the surface book as well. The base model uses a core m3 processor so it's fanless. MS also released a new keyboard cover which includes a fingerprint sensor (along with larger touchpad and redesigned keys). It's backwards compatible with the surface pro 3 so you can reap the benefits even with the older sp3. The surface book has a fancy hinge for the attachable keyboard: The keyboard is pretty essential for the surface book as it functions in 3 ways. Your usb connections and sd card slot, extra battery, and dedicated gpu (if you added that option) is housed in there. The surface connector is on the tablet and keyboard dock. Connecting your charger into either one will charge both devices. The nvidia gpu it uses is a bit of a question as all the descriptions are just saying dedicated nvidia gpu. It's most likely a custom gpu that Microsoft and nvidia partnered up with to create for the surface book specifically. We'll have to wait for surface book benchmarks to get a real picture. Both sp4 and surface book will use Microsoft Hello for facial recognition with skylake's realsense camera. Neither device have usb-c which is funny since at the same event, MS unveiled the new lumia phones that have usb-c.