According to the Google Agency newsletter, they are rolling out a new user type in AdWords: email-only.
Email-only users will be eligible to receive system alerts (billing, disapproved ads, etc.) but will not be able to log into accounts directly. To help streamline communications across multiple accounts, multiple email-only users can be added to an individual account, and the same email can be added to multiple accounts. You can invite email-only users in the Access section under your My Account tab in any individual client account.
