The new Migration Law for Mexico (originally passed in May 2011) was published on 2012-Sept-28 and will take effect 30 working days from that date (early November). Many articles in the law are intended to help protect immigrants from countries south of Mexico and to improve the rights of women and children. However there are also major changes that will effect temporary and permanent residents, especially ExPats from other countries.
Many of the details are missing such as income levels required for temporary or permanent residence. The new Residente Temporal visa which will replace both No Inmigrante and Inmigrante visas is bound to have new income requirements. Also upon applying for a Residente Permanente card there is no income level mentioned. Of course the reason to be interested in a permanent resident card is that it means no more visas or renewals.
It also states that you can apply for a permanent resident card after 4 years on a temporary visa but does that mean on the 4th renewal of your current visa. For instance, I'll be entering my 7th year next renewal but it will be my 2nd renewal on my current visa. That point may be moot since the law also states you can apply for permanent status at any point. Then there's the issue of regional interpretation which many of us have experienced or read about in the past.
Here's one persons take on the changes from San Felipe Life He also has PDF files in English to down load from his site. You can also go to the official Mexican site Diario Oficial de la Federacion and read it online. If that link does not come up in English you can use their translator on the right sidebar.
Here is another aspect to the new regulations from Rolly Brook's web site
You will be able to renew your Residente Temporal for periods of one to four years with costs being: (in pesos, of course)
$3,130 for a single year
$4,690 for two years
$5,940 for three years
$7,040 for four years