Justia.com is now providing free daily and weekly opinion summaries for the US Supreme Court, all US federal courts of appeal, and state supreme courts. As well, free weekly opinion summaries are available for nearly sixty areas of practice. These, it would seem, are delivered by email; there doesn't seem to be an RSS feature. If you're curious, you can look at a sample daily email for the US 9th Circuit Court of Appeals or a sample weekly summary for the practice area of environmental law.
Needless to say, this is a powerfully impressive service and a considerable contribution to the open access to law movement.