You do not have to surrender your natural Citizenship to be granted full resident status in Mexico. Full resident status entitles you to all rights and benefits of a Mexican National (live, work, claim state benefits and to pay taxes) but you cannot vote in Mexican elections.
Wow! Mexican immigration is less stringent then I would have thought. I was considering buying property there at some point, I know that will be a hassle. I just hope US/Mexico relations don't get too strained.