This bloke
here agrees that it will be different to the 30s too: As in worse.
But I personally think that Europe will come to its senses and act before it lets one of its major countries default.
I'd like to remind everyone that the failure of the Austrian bank Credit-Anstalt made the Great Depression much much worse:
http://www.businessweek.com/magazine/content/11_18/b4226012481756.htm
I wouldn't be surprised if Austria is in the cross-hairs again. Why? Austrian banks have lent heavily to Eastern Europe, especially Hungary which is now in deep trouble largely because its householders took mortgages in Swiss Francs. With the collapse of the Hungarian currency the size of these mortgages has exploded. The Hungarian government is trying to force banks (such as the Austrian banks) to take large losses. The country as a whole is becoming a basket case with the government seizing private pensions (their equivalent of super), taking control of the Central Bank and implementing media controls. They have come crawling back to the IMF recently though. And Italian banks have large exposure to Austria.
Here is a good article on the line of dominoes from Eastern/Central Europe to the West:
http://www.golemxiv.co.uk/2010/12/dominoes-falling-from-the-east/
Other problems include the huge private debt in "Northern countries", especially the Netherlands (housing bubble again):
http://blogs.wsj.com/brussels/2011/12/05/household-debt-woes-dutch-edition/
Norway is another culprit here. The northern countries going down could be another trigger too.
Then there is the hugely indebted UK system which is also the world epicentre of financial engineering.
Then there is the big one in which the ECB, by taking on anything as collateral, could very well go broke if one of the PIIGS defaults.
The problem with Europe (and most of the world's financial system) is that that you try to stop one leak and another one appears somewhere else. And since everything is so hyper-connected and opaque there is no way they can control the system. And in fact if they try to control the system by say increasing banking reserves it could very well bring about the disaster feared. The problem is that by trying to stop the disaster, they simply drag more and more institutions into the mess.
One thing I find hilarious about governments is that they always seem to do the wrong thing - they bailed out the banks when they should have let them fail. However then they tried to be too clever by half by getting Greece to default on half of its privately owned debt without triggering a default event and CDSs to punish the speculators. However, of course the entirely predictable thing happened. If the sovereign default swaps are effectively worthless then the interest rate they will charge on the debt will be higher, thus triggering the current Italian crisis. And for what little gain? Idiots.
Still I do agree with the idea that they won't let any of the PIIGS default. I'm willing to bet the first country to leave the Eurozone is Germany. It is usually the strong countries that rebel because they believe they can afford to act alone.