KASO - yes - you are correct - the Denon has 7 channels of amplification built in. So if you don't use the surround back channels (the 6 or 7 in 6.1 and 7.1), you can use them to independently power zone 2.
What is cool is that you can be watching one source in zone 1 in 5.1 surround sound, and have zone 2 playing a totally different source at a different volume.
The remote control has different modes to control the receiver. So you put the remote in Multi, and it controls the inputs, volume and tuner channels for the 2nd zone. This alone sold me on this receiver! Of course the incredible sound quality and processing didn't hurt either! :)
So if you wanted to, you could get an IR repeater in the 2nd zone, with a programmable remote, and teach it the Denon's 2nd zone commands. They actually have a diagram of this in their manual.
Go to
www.denon.com and check out the 3802. They have the manual (PDF) online. I am upgrading to that this week, as it adds DPLII, and some more refinements to the power supply and circuitry. They took an incredible product and made it better!
Sound & Vision tested the 3801 and the power was 92W X 5 all channels driven, 125W X 2 and 85W X 6 all channels driven. There aren't many 100W receivers out there that can even push 5 speakers with 85W all channels driven. The Yamaha RXV1000 comes to mind - it "only" pushed out 78W X 5. So yes, these Denon receivers are really as good as everyone says they are. At least in my BIASED opinion. :)
Bryan