It appears that SPAN-like margining has been expanded to cover more products. As the article suggests, this should enable the little guy to significantly increase his buying power. Other unintended consequences (put skew) are subject to debate and it will be very interesting to see what effect this has on the market once fully implemented.
http://www.insidefutures.com/article/3478/TRADING%20FLOOR%20SECRETS:%20New%20Margins.html
http://www.insidefutures.com/article/3478/TRADING%20FLOOR%20SECRETS:%20New%20Margins.html