The following is taken from a Jan. 24, 2010 press release by the Paulus Institute in Washington DC, which is sponsoring the Mass, commenmorating the fifth anniversary of the pontificate of Pope Benedict XVI.
The mass is to be celebrated by the Vatican’s Cardinal Castrillón Hoyos, who reportedly has stepped aside following reports he wrote a letter in 2001 praising a French bishop for refusing to hand over to the police a priest who had raped children. Organizers are now reportedly searching for a replacement prelate, one immersed adequately in the Latin language and ceremony.
The mass, set for Saturday, has been marketed as "the First Traditional Mass at the National Shrine’s High Altar in 45 Years." It is to be "commemorated in the Great Upper Church of the Basilica of the National Shrine of the Immaculate Conception, Washington DC, by a Pontifical Solemn High Mass in the 'Extraordinary form'—commonly known as the 'Traditional Latin Mass' or 'Tridentine Mass'— celebrated by the Vatican prelate Dar'o Cardinal Castrillón Hoyos of Colombia."
By way of background, according to the Paulus Institute: