The new branch of the Kindle Store stocks over 2 million titles including 70 thousand titles in Spanish, Nahuatl, and other languages indigenous to Mexico. Amazon is also selling the Kindle and Kindle Paperwhite locally with prices starting at 1,399 Mexican pesos ($105 USD) for the basic Kindle and 2,399 Mexican pesos ($180 USD) for the Kindle Paperwhite.
That catalog of 70,000 titles is somewhat larger than the selection Amazon offers on Amazon.com, and it is also greater than the 60,000 Spanish language titles claimed by Argentina-based BajaLibros. Aside from iBooks, that ebookseller (which recently expanded into the US market) is probably Amazon's strongest competitor in the Mexican ebook market.
In addition to the new ebookstore, there's also a new branch of KDP for Mexican authors and publishers (here).