I had mixed feeling about that. On the one hand, the no vote as a means of stopping the erosion of Swedish generous welfare state makes sense, but I am not sure whether it is the best or effective strategy - or that Sweden's welfare state is being seriously eroded, it still accounts for 34% or so of the GDP. On the other hand, the euro looks like a challenger to the dollar and the US hegemony in the world trade - so a strong euro is a good thing. Sweden joining the eurozone would certainly strengthen the euro.
Wojtek