Read some recent news on this:
*****://blogs.oracle.***/FinancialsMkting/entry/idea_of_u_s_companies
http://in.reuters.***/article/2012/07/16/us-accounting-idINBRE86F0MI20120716
http://***.accountancyage.***/aa/news/2198009/us-won-t-adopt-ifrs-for-at-least-five-years-says-aicpa-chief