Not sure Mexico 'll get free games, I tested again my 3ds with different region settings (New York, USA) when launched Nintendo Video it says "Nintendo video service is not available in your location. You cannot download videos". It sure is available in NY and I think Nintendo video cant be used when the region registered in 3DS doesnt match that of your connection/router/server. This are great games in an exclusive one-time oportunity I dont wanna miss.

One could lose an Ambassador status changing back to Mexico, I also thought to hold out until the end of the year with the 3DS region set to USA (even if I have no Nintendo Video for that time and mess my SpotPass) to get all the free games. But I also thought the Ambassador program may not work if my real location is not selected on the system settings (in the way Nintendo Video does), and I could just change nothing and hope for the chance of the program and games being available in Mexico (both big risks IMO)... What will we do not-sure-if supported countries? what would you do if it were you EU, NA?

EDIT: I think I should decide before the registration limit date expires on Aug.11
I can DL Nintendo Video and works fine with my real location selected on the system settings (Mexico)
I am still waiting NOAs email reply to one of the 3 Ive sent them about this almost 2 weeks ago

IMPORTANT UPDATE @8

Well, you can still use the shop if you set it to a different region? But no Nintendo Video, that's strange.
Would you be able to hold out until the end of the year to get your free games? At that point you can just switch back to your regular region and enjoy Nintendo Video. ...Or can you not get NV at all? >.>

...Although now that I think about it, a person is given Ambassador status if they connect to the shop before August 12. So even if you do lose that status when you change regions, you can easily get it back by just connecting to the shop again.

I hope I'm making sense with all of this, it's kind of hard to work out the specifics of your problem based on the post, but after almost 100 views and no response on this thread, I thought I might as well chip in some advice. (There is an FAQ, though...)

Sorry for poor explanation details english isnt my primary language, thanks for your help! Edited OP for better understanding

Yes, I download get Nintendo Video and works fine when I have my real location selected on the system settings. (Mexico)

I also thought to hold out until the end of the year with the 3DS region set to USA (even if I have no Nintendo Video for that time and mess my SpotPass) to get all the free games. But I also thought the Ambassador program may not work if my real location is not selected on the system settings (in the way Nintendo Video does), and I could just change nothing and hope for the chance of the program and games being available in Mexico (both big risks IMO)... What will we do latin gamers? what would you do if it were you EU, NA? (Before the registration limit date expires on Aug.11)

Ambassador status is stored on Nintendo's servers, so I would guess that you can't lose it in one region by switching to another. I don't know for sure, though, so if it were me, I would contact Nintendo and ask if Mexico will get the free games.

@Rift: Thanks, you've bought a point I hadnt considered.
I hope it will work like that since I have connected from both regions, safe bet for me.
I am still waiting NOAs email reply to one of the 3 Ive sent them about this almost 2 weeks ago

EDIT: Mexican official magazine posted a translation of the press release, but its just a translation no new details, not necessarily meaning the program will be effective in Mexico. I contacted them about this and as usual they know nothing, their information is often late and incomplete, Nintendo should be more serious and strict when choosing their official international representatives IMO.

Try contacting Nintendo of America for details about Mexico.

I am still waiting NOAs email reply to one of the 3 Ive sent them about this, intl. phone is very expensive for me but thanks!

Today I got both, a Notification and a post on eShop news clearly stating "You are a Nintendo 3DS Ambassador" having Mexico, my real country in system settings. I have language set to englsh and I've also used the shop from the US but I dont think that really matters. So for people like me not sure if the program will reach your region, I think geting this notification by this days is so far the best confirmation we were waiting for.

EDIT: NoA finally e-mailed me back, confirming it works in Mexico, but didnt answer about the rest of latin America.