Not really. China is increasingly buying other assets, instead of Treasuries: stocks, companies, real estate, etc. In the end, they will own the USA.
In fact this scenario was famously depicted by Warren Buffet in his "Squanderville versus Thriftville" essay: http://www.tradereform.org/2008/03/squanderville_versus_thri... Want some concrete examples?:
The chinese Lenovo acquired the IBM PC division in 2005.
Chinese oil and gas acquisitions: http://blogs.forbes.com/christopherhelman/2011/02/10/watch-o...
China's investments in U.S. up sharply: http://articles.latimes.com/2010/mar/04/business/la-fi-china...
