With regard to an amended volume submitter plan, what is the current applicable deadline for an employer to submit a determination letter application?

Is it the two year period yet to be announced by the IRS for employers to adopt plans and submit determination letter applications that will end some time prior to the end of the six year remedial amendment cycle (described in Revenue Procedure 2007-44 section 19.05)? Or is it January 31, 2012? January 31, 2017?