Google has been teasing a mobile index, separate from their desktop index, for some time now. Today at Pubcon, Gary Illyes announced that this index will be launched within just a few months. This sounds like it will match up close to the date when intrusive interstitials are devalued in mobile results.
Illyes then continued on to say that the mobile index would be treated as the primary index. Currently, Google extracts data from desktop content to determine mobile rankings. This raises several questions. Will the mobile index only include mobile-friendly pages? What will the role of content be, since it often takes a backseat to functionality in mobile designs?
What are your expectations for the mobile index? What precautions will you take to preserve your rankings?