Update: As noted below, the terms of service indicate you can opt out of this particular clause by mailing a letter to Microsoft. That’s apparently not the case, as Kotaku has been told you must agree in order to use Xbox Live. The following statement was sent along with that clarification:
Users must agree to the new clause to the Terms of Use in order to continue using Xbox LIVE. Changes to the Terms of Use are designed to ensure that our customers have an easy way to file a dispute without requiring formal legal action. They may now bring a dispute to our attention by filling out a simple Notice of Dispute form found at www.xbox.com/notice and mailing in documentation in support of their claim. We will then work to resolve the dispute to their satisfaction within 60 days. Any customer unsatisfied with the outcome of this informal process may easily initiate arbitration with the American Arbitration Association.
