Falling Dollar

From   http://www.time.com/time/magazine/article/0,9171,1666266,00.html
"  It's not that we Americans have gotten a lot poorer. It's that we might be about to. "

What is average share of the greenback in big economies' (EU, Russia, Australia, India, China) treasury reserves? 60%? 70%? 80%?
Isn't it the cheapest option for the world - to bailout America, rather then to let it declare bankruptcy?

And some links to other articles on the topic:

An article from March 2009:
http://www.reuters.com/article/reutersEdge/idUSTRE52M5UZ20090323

http://blogs.reuters.com/great-debate/2009/10/13/dollar-faces-long-journey-downward/

http://www.reuters.com/article/usDollarRpt/idUSN1318753620091013

http://yglesias.thinkprogress.org/archives/2009/10/the-falling-dollar.php

http://buzz.yahoo.com/article/1:financial_tim933:fa2384c7b4f2bf161cdd1bacc9caf09e/Obama-under-fire-over-falling-dollar 
and 
http://www.ft.com/cms/s/0/08ca4832-b36a-11de-ae8d-00144feab49a.html?ftcamp=rss&nclick_check=1

http://www.kippreport.com/2009/10/is-the-dollar-dying/