Why's the dollar (euro, pound, etc.) going down against the peso? The primary reason has to do with the agreement with the World Monetary Fund (FMI). Not only does the agreement bring some certainty (finally) to some important issues that have been floating around for months (tarifas/subsidios, brecha cambiaria, reservas del Banco Central, higher interest rates and the possibility of default are some principal ones), but the government has acceded to the demands of the FMI in most cases (including shrinking the brecha cambiaria). A good summary of much of this may be found here (Spanish):
Peso argentino en mercados alternativos se recupera tras anuncio de acuerdo con fmi
www.lanacion.com.ar
We're also heading into harvest season, with the prices of grains at or near records, and with the shrinking difference between the official dollar and the others, the farmers should be more willing than in recent years to sell their crops early, adding to the pressure on the dollar.
So don't be surprised if the dollar blue, the contado con liquidación, the dolar MEP/bolsa, the Western Union transfer rate, etc. continue to go down, at least in the next few months, and perhaps longer.
We could see the dollar steady and even go up a bit, keeping pace with the official dollar, but the FMI, with this agreement, is trying to put Argentina (as much as it can), on the right track, so I wouldn't expect the dollar to just turn around and run back up to the recent high prices we'd become accustomed to, unless Argentina breaks the agreement or really screws up in a big way (or if, for some reason, the agreement gets scrapped).