Can Americans use the ambassador program?
what is the wii ambassador program? O_o
You may find any and all information regarding this promotion which is only happening in the United Kingdom at this time, by visiting Nintendo of Europe's webpage by Clicking Here. That page I linked will explain the program to you. Please note it is only happening in the UK at this time and not in North America.
Additionally, no details have been revealed at this time if it will be coming to North America anytime soon.