Cardinal Bergoglio was one of the first bishops in the world to respond to Benedict XVI's Summorum Pontificum

This was added to Pope Francis' wiki page sometime last night. 

Cardinal Bergoglio was one of the first bishops in the world to respond to Benedict XVI's Summorum Pontificum by instituting a regular traditional Latin Mass in Buenos Aires within just two days of the Papal motu proprio.^[67]

 Source: Rubin, Sergio (17 September 2007). "Regresó la misa en latín, con mujeres cubiertas por mantillas". Retrieved 14 March 2013.

From the article:

La celebración se produjo 48 horas después de que el papa Benedicto XVI firmara el decreto (motu proprio) que libera esa modalidad. 

Fr. Finigan also posted on this topic.  

UPDATE: Rorate has posted this afternoon with this response:  How Summorum Pontificum was blocked and trampled on in Buenos Aires: facts, not fantasy and disinformation

And so what was the great and generous application of Summorum Pontificum in the Archdiocese of Buenos Aires? One Novus Ordo-TLM hybrid once a month. And, as it happens to any badly celebrated Latin Mass, the number of attending faithful fast dwindled from one hundred to a handful. And, naturally, it was discontinued. So, as correctly mentioned in WikiMissa, there is currently not a single actual Traditional Mass according to the 1962 Missal celebrated by diocesan priests of the Archdiocese of Buenos Aires. And every priest who tried to truly implement Summorum in his parish  - that is, out of their own initiative, without "authorization" from the Bishop - was ordered to stop.

continue there (if you care to read up on the issue)