According to this article Juan Martinez let it slip that SLog2 may be coming to the FS700 in a future firmware update.
NextWaveDV – Why the Sony FS700 won NAB Show 2013 (http://www.nextwavedv.com/why-the-sony-fs700-won-nab-show-2013/)

Here is a test of the Beta Firmware S-Log2

FS700 + S-Log2 : SUNNY DAY IN THE PARK on Vimeo