In 2008, when the financial crisis was taking form, it was the US who sneezed and the world who caught a cold. This principle still applies, but now the US is slowly emerging from sickness while the euro zone still deals with the very real issue of a potential breakup, in one form or another. The US still has many issues, debt being one of them, but the States have the benefit of being a single country that can act in unity -- and the euro zone is not.
As far as the markets today go, equities are actually well supported; yesterday the US indices were mixed but very flat overall, and overnight APAC closed with a slight negative bias, but European stocks are up well over 1% on average. Currencies, however, did take more notice of rumblings about a Greece exit from the monetary union. The euro continued to fall commitedly, taking out the 1.26 level, but it has been a slow grind down as sentiment drives the price action without any real or official news on the situation. The Canadian dollar also traded lower during the dollar bid, but has not fallen as much as the EUR and other risk-sensitive currencies, like the AUD, which makes sense economically. The Loonie has not correlated with the fall in oil, which could signal more downside movement for the northern dollar.