The announcement of the nationalization of the oil company YPF , controlled by Spain's Repsol , and the transfer of 51% of its shares to the Argentinean government, sparked many reaction on the Argentinean blogosphere, both in favor and against. In general, as with other issues in Argentina, opinions are divided between those in favor and those opposed to the government of Cristina Fernandez de Kirchner. 
In ArtePolítica  [es], a blog close to Kirchner party, Sebastian says that “Repsol-YPF was always a shame” and states that,
El modelo Petrobras parece a priori el más adecuado: capital mixto y parte en la bolsa, gestión muy profesionalizada, y control accionario mayoritario por parte del estado nacional y de las provincias petroleras.
In IndiePolitik  [es] they make a selection of quotes by politicians and newspaper columnists that are against the measure, although in an ironic context based on the question,
¿Qué dudas caben de que la expropiación de YPF es una medida, además de histórica, correcta, si los que se oponen son el FMI, Macri, Carrió, La Nación, la UCR dependiente, De Narváez y Clarín?.
The Agenda Digital  [es] blog, from the official news agency Telam, summarized the impact of the news on Twitter.
At Saber Leyes no es Saber Derecho  [es], some of the consequences of the nationalization are discussed, particularly from a legal point of view of the corresponding bill  the President sent to Congress, which is currently under discussion.
Economía Posible  [es] indicates that during the Kirchner governments there was a significant drop in production, and wonders if “the same responsible people for the energy policies of the past nine years say they're going to ‘save us'”.
Among the blogs linked to the Union Civica Radical (Radical Civic Union ), a traditional Argentinean party and the opposition today, Hernán Haynes  [es] said that the nationalization of YPF goes against the Argentinean Constitution.
In Comunicación Ambiental  [es] Eduardo Soler wonders why the announcement of nationalization had no further reference to clean energy while it did mention “unconventional oil”, which usually requires more complex technology for extraction.
Finally, looking beyond the impact of the nationalization of YPF on Argentina, Vaca.org [es] analyzes the case in the context of changes in the global economic system from the rise of China and developing nations.