Sailor, just got some clarification and here is what I understand at the moment: There is a proposal, not yet law, for a 72 hour visa free for tourists who are in-transit from one location to another with 3 Russian cities as stop over points. This is not designed to fly to Russia for 72 hours and then return home.
The 3 cities are Moscow, St Petersburg, and Kazan. Your flight must transit there and you must stay in that city during the 72 hours. For example you cannot fly from the USA to Moscow and back to the USA nor can you fly to St Petersburg and then travel on to Volgograd or Novosibirsk, etc. It applies to in-transit flights only and only to those 3 cities. Cruise ships will have the same privileges for St Petersburg and Moscow. Moscow is considered a port city via the river lock system and a lot of European river cruises have Moscow as an itinerary.
Exceptions: athletes, coaches, referees and foreign delegations taking part in the 2014 Winter Olympic Games in Sochi get a 3 month entry pass without a visa. In May President Putin signed a decree (executive order) that athletes in any international sports venue can enter visa free for organized events. They are expected to stay in the general area of where the event takes place.