Of course there are differences, but there are also plenty of similarities. According to the article, Greece's economy is exactly where the US is headed, even if we're not there yet. Its foundation is borrowed money spent by government to give its citizenry everything it wants. It has regulated everything to the nth degree, created government monopolies in important industries, and made it difficult for businesses to do business within its borders. Sounds pretty similar to the US to me.
United States - Labor force - by occupation:
farming, forestry, and fishing: 0.7%
manufacturing, extraction, transportation, and crafts: 20.3%
managerial, professional, and technical: 37.3%
sales and office: 24.2%
other services: 17.6%
note: figures exclude the unemployed (2009)
Greece - Labor force - by occupation:
agriculture: 12.4%
industry: 22.4%
services: 65.1% (2005 est.)
Not, even, close.
Greece - Imports - partners:
Germany 13.73%, Italy 12.71%, China 7.08%, France 6.1%, Netherlands 6.02%, South Korea 5.68%, Belgium 4.34%, Spain 4.08% (2009)
United States - Imports - partners:
China 19.3%, Canada 14.24%, Mexico 11.12%, Japan 6.14%, Germany 4.53% (2009)
Source: CIA world factbook. You are also comparing the ~140th economy in the world with #2.