As I reported today on The Ticker on Tennis.com, the ITF has decided to change its qualifications rules for the 2016 Olympics. After the 2012 Games, a player must make himself or herself available to play Davis Cup or Fed Cup four times in an Olympic cycle. Currently, players only have to make themselves available for two ties in the two prior years to the Olympics. Maria Sharapova has already gone on record with her objections to the changes.
The ITF sees it differently, saying, among other things: