Since March the main Bay runway (31L/13R) has been closed for major maintenance. This runway usually handles 30% of the traffic at JFK. About 10,000 feet of this runway is to be re-opened on June 30th. Since March unique and challenging runway combinations have been used to maintain the required capacity.
Personally I feel the airport and ATC have done a stellar job keeping things going. But it is always an interesting ride into JFK. About 50% of my flights get in there with a non-precision approach.