Anyway, this is what's going on lately. (I'll try to keep this updated)
27.3.2016: Uber officially starts recruiting drivers. Uber launch seems imminent: http://www.infobae.com/2016/03/27/1799470-uber-da-su-primer-paso-el-pais-y-convoca-conductores-buenos-aires
12.4.2016 (10PM): Uber officially launched: http://www.infobae.com/2016/04/12/1803830-confirmado-uber-se-podra-usar-las-1600-buenos-aires
12.4.2016 (6PM): Buenos Aires police seized Uber driver's car. Fined him with ARS$77.000 (aprox US$5.133): http://www.infobae.com/2016/04/14/1804342-la-ciudad-secuestro-el-primer-auto-uber-y-multo-al-conductor-77-mil-pesos
13.4.2016: Buenos Aires justice says that Uber is "illegal". Uber can't operate in Buenos Aires[1]: http://www.infobae.com/2016/04/13/1804173-la-justicia-portena-ordeno-suspender-la-actividad-uber
15.4.2016 (Today): Huge strike by taxi drivers. Chaos in Buenos Aires: http://tn.com.ar/sociedad/arranco-el-piquete-anti-uber-una-hora-antes-de-lo-previsto_666026 * http://www.infobae.com/2016/04/15/1804652-los-taxistas-cortan-el-transito-uber-y-las-redes-sociales-volvieron-estallar * Twitter https://twitter.com/search?q=uber%20near%3A%22Argentina%22%20within%3A15mi&src=typd
[1] It's just Buenos Aires justice, idk what's going on with the federal justice.