What is the current and future market size and landscape for
foreign-language learning in the U.S.?  Can you give as detailed an
analysis as possible including categories such as foreign language,
delivery sytem (e.g. audio CDs, CD-Roms, Internet-based, classroom),
product pricing, company, demographic, time spent studying,  etc.? 
Can you point to further sources of information if not provided here? 
I am particularly interested in the chinese-language learning market.