Based on how Apple model names flow along their generation times, the newly released model names could be that of 17" MBP. However, with there being 5 distinct model identifiers, there's a few other things it could be.
New identifiers: possibilities(first has higher chance)
MD71x possibilities=Mac Mini, iPhone, MBA(small tweak)
MD76x possibilities=Mac Mini, iPhone, MBA(small tweak)
ME17x possibilities=Mac Pro, MBP 17, MBA(major update), iPad mini
ME18x possibilities=Mac Pro, MBP 17, MBA(major update), iPad mini
ME91x possibilities=MBP13/15, iMac(?)
This is just my own guess.