Most of the H1Bs are Indian and Chinese. Once they get domain experience in the US, they will become US-based managers for off-shore teams in India and China. Outsourcing may be rampant, but there is still bush back by American managers who have difficulties communicating with off-shore teams (language barrier, cultural differences, time difference, etc.)
Once the old-school middle management is replaced with Hindi and Mandarin speaking individuals - it's smooth sailing for outsourcing. Also, their hiring preference will be more towards hiring from/in their native county, because they are naturally more connected in their native country than the new host country.