A note in the Origin Terms of Service outlines conditions that may provoke Electronic Arts to delete user accounts from their fledgling online service, as the section on "Content and Entitlement Availability" reserves their right to delete accounts that have been inactive for 24 months. This caught the eye of Rock, Paper, Shotgun, and they have inquiries in to EA asking whether it is correct to think this means it will be possible to lose access to achievements, DLC, or even games as a result of this, but this has not yet inspired a response. Here's the wording of the clause in question:

Entitlements may only be held in Accounts belonging to legal residents of countries where access to and use of Content and Entitlements is permitted. Entitlements may be purchased or acquired only from EA or an authorized retailer. EA reserves the right to refuse your request(s) to acquire Entitlements, and EA reserves the right to limit or block any request to acquire Entitlements for any reason.

We do not guarantee that any Content or Entitlement will be available at all times or at any given time or that we will continue to offer particular Content or Entitlements for any particular length of time. We reserve the right to change and update Content and Entitlements without notice to you. If you have not used your Entitlements or Account for twenty four (24) months or more and your Account has associated Entitlements, your Entitlements will expire and your Account may be cancelled for non-use. Once you have redeemed your Entitlements, that content is not returnable, exchangeable, or refundable for other Entitlements or for cash, or other goods or services.