Not to be a pessimist,

but I have started my day by watching CNBC, The Financial Channel, nearly every morning for MANY years, and have come respect to the views and insights of one guy, Art Cashin, over all the other pundits, as he has consistently been able to see what's going on, and explain it. He had a VERY interesting piece on the show this morning that makes a lot of sense. Here's a clip (a little over 3 mins), where he makes a startling prediction in the last half minute.
http://video.cnbc.com/gallery/?video=3000090146&play=1

In a nutshell, Art says that Germany's not going to continue to bail out the Greeks, esp after the last election where the people voted in a Socialist gov't that is nullifying the austerity agreements already agreed upon. SO, just a (small) matter of time before Greece leaves the Euro Zone. As that time approaches, Greeks know that the banks will close for a week or so and re-open w/drachmas instead of Euros. In the lead up to that, Greek citizens (who want the buying power of the Euro) will make a run on the banks, and that (bank run) contagion will immediately spread to Spain, Italy and Portugal, who are also hopelessly under water, and the reaction will be 'cataclysmic'. Seems crazy, but very real, and Art does know what he's talking about, most of the time.