The US and the dollar: depreciation and consequences

US dollar is going down because of the twin defict and the effects of the 2008/2009 critical point of the international economic crysis. This is going to lead the world to a new way of saving and a new currency. I already said that the euro and the yen are the two alternatives, but the yen has been in zero interest zone for too long and the Japanese economy has been asleeped as well. So, the only new way of international savings is the euro; this is going to produce an appreciation of the euro and the question is: how strongly? Well, the answer is fast and strong. Yes, what you've read is true and this is by this reason: the savings of the world are put in US dollars so when a punch of dollar depreciation comes the savers take their dollars and they transform them into euros and this process continues until there isn't anymore dollars in savings or when a political movement cancels the appreciation of euro.
Ok, until here nothing happens. But, is it good for Europe the fast appreciation of euro? In a hand, yes, because they can take of the world more resources and products with the same amount of euros. In the other hand, a disaster is just at the end of the corner: Europe losses competitiveness in their for export products and their trade balance gets destroyed, a descendent spiral of economic activity comes with unemployment (as well we are seeing it in Spain, Italy, Germany and Greece nowadays), MASSIVE capital flight and this disperses to the international economy in the form of a new worldwide capitalism crysis.
I have to say that this is entirely a suposition of what would happen in the case that the US and Europe don't do anything about this situation, which is completely untrue and it won't happen. It is more realistic to think that the US and Europe are working toghether to solve this out.

Dedicated to my friends, students of PENN (University of Pennsylvania), specially to John Marcus Kane. Greetings from Argentina.