As for the next Xbox system, it is called Xenon. I have a buddy who is a Vendor at Microsoft's home entertainment division at Issaquah, WA. Bungie's office is somewhere in Redmond, WA on the Millenium Campus which is the Xbox hardware and games division. I should know since I play test there.
Anyways, yes it is true that Microsoft wants to get Xenon to be released first before Nintendo and especially Sony fon the next generation consoles. Sony has been dominant in the console war. MS's goal is to beat out Sony in releasing so they can get the market share.