You use two completely opposite rationalizations for NE and MIN.....You say that it will help AP by getting defenders out of the box, but you also say it helps BGE by NE running more. I could easily argue that by saying MIN will now pass more(hurting AP) and NE will have more 8-9man boxes w/o Moss.....interesting POV you have. Either way, I think this trade makes sense for both teams moving forward.
I guess I should have clarified more. As it stood before the Moss trade, the Vikings WR corp was mediocre at best. Defences could key on the run as the secondary didn't need as tight of coverage as if they had a big play receiver to worry about. Now they'll need to commit another DB to pass coverage. I agree that the Vikes will likely pass more now, but AP should have the opportunity to break off a few more long runs. NE relied heavily on the pass and didn't rush the ball much (which should have helped the NE RBs have bigger holes, mind you) but the running game has never been a focus or terribly strong for NE. I think BGE will get more opportunities now that Moss is gone, so hopefully that will help his numbers. But, like you say, defences may now throw another guy into the box and it'll end up being a wash.
All in all, I agree with it being good for both teams, though fantasy-wise it'll probably end up hurting the Vikings WRs who aren't named Moss.