Well, the MW3 Facebook page has posted a video of a in-depth review of the game, by creative strategist Robert Bowling. From the Facebook page:
Robert Bowling from Infinity Ward talks in-depth about the new Prestige Shop coming to Modern Warfare 3. Every time you prestige in MW3, you’ll receive a prestige token. Use it to unlock rewards like double XP for a limited time, an extra custom class, or choose one piece of gear from your custom class to keep unlocked from rank 1 of future prestiges.
If you’ve ever prestiged in Call of Duty: Modern Warfare, Call of Duty: World at War, Modern Warfare 2 or Call of Duty: Black Ops you’ll get tokens that you can use in MW3 on day one! The weekend of October 27th, we’ll be running Double XP for MW2 and Black Ops, so be sure to rank up and collect those prestige tokens.