They have announced a number of different CPU options for the late 2012 mac mini. I'm interested in the 2.6 Ghz Quad-Core i7. Should I assume that's the i7-3720QM processor? Is there an official document that I missed that details this.
There's no public Apple document that has this info. But, with a little bit of info from Intels' CPU specs site, you can assume that's the one.
There are sites which show you that info also (to see if your assumption was good):
According to the EveryMac site, the 2012 Mac Mini use the following chips: