There's no significant cooling from the current Iceland eruption, as the SO2 is not being ejected with enough force to reach the stratosphere. Being it's in the troposphere, it washes out fairly rapidly. It's also at a very high latitude, so there's comparitively little sunlight to reflect. Volcanoes that change the climate generally need to be in the tropics, and need to make very big booms. Exceptions to this rule come from insanely massive Icelandic eruptions, like Laki in 1783.
As far as Iceland goes, even Christmas is scary. Let me introduce you to Jólakötturinn, the Icelandic Yule Cat. He's a huge wildcat who eats anyone who doesn't wear a new piece of clothing on Christmas. An old Icelandic poet wrote a classic poem about him, and Björk (there are apparently no other musicians in Iceland) set it to music in a tune that everyone in Iceland now knows. It's like their version of Bing Crosby singing "White Christmas", except it features a vicious beast eating the fashion-deprived on Christmas. Even if Björk normally drives you insane, this is worth a listen.