My prediction is that the Xbox3 wont be geared towards gamers (and all youse gaffers will CRAH)
Oh it'll have a respectable processor, a decent GPU, and a healthy dose of extra ram, but the thing will be modern existing tech, not cutting edge. It'll be priced slightly lower, definitely less than $400 for the cheapest SKU, and be focused around using the Kinect (2.0?) as a living room centerpiece. It'll have a sizable HD focused around downloading media, exchanging pictures, but more importantly, purchasing living room apps. MS will attempt to do what apple TV could not and take over the living room using the xbox brand and kinect functionality as a trojan horse. They will attempt to start a new cheap app market centered around micro-content in the living room. It'll also attempt to replace cable as the standard provider for movies and shows. Gaming will of course be emphasized each year at E3 or other trade events, but really they'll be focusing more on ways to make money through digitial distribution of products other than games. The thing will have full cross compatibility with windows 8 and allow seamless media sharing between multiple devices. Windows phones and laptops will automatically sync folders you want to share between devices when within your home network. There will be apps that work on both phones and on the Xbox3 (via kinect). You'll be able to communicate and share content with other people on the xbox live network through their phone, computer, or console.
That...is my prediction. *removes tinfoil hat*