The U.S. Department of Health and Human Services today put out this detailed fact sheet about "grandfathered" health plans, which wouldn't have to comply with some elements of federal health reform.
The document details what benefits ALL health plans (grandfathered or not) must offer, starting Sept. 23, 2010. Among these: No lifetime limits.
HHS has also come up with a new regulation to prevent health plans from using grandfathered status as a shield to avoid providing consumer protections. The fact sheet has more details on this.