According to the Huffingtonpost on June 1 2011, the IMF was expecting some heat: The International Monetary Fund is ready to be hacked. Source Huffington Post(repost?)
I just find that sentence extremely hilarious, maybe it's just me.. :]
Anyway there was so much ph34r that cables were unplugged: The concern about the attack was so significant that the World Bank, an international agency focused on economic development, whose headquarters is across the street from the I.M.F. in downtown Washington, cut the computer link that allows the two institutions to share information. Source: New York Times
From what I understand the attack took place (or started) a few months ago, way before the above cited prediction.. .
You can follow up on #IMF@twitter.