Im an aerospace major.
Since I just took my final on aerodynamics yesterday, this is still fresh in my mind and Ill put in my 2 cents.
First, lets relate this plane to our own running bodies.
The thrust from say, jet engines, is comparable to our leg muscles.
Both will exert JUST enough force/energy to keep the person/aircraft in the same location on the treadmill.
The thrust from the jet engine will keep the plane moving "forward" on the mill, but really it is in the exact same place, just as our legs keep us in the same exact place in the room (on the mill)
The thrust produced pushes the body of the aircraft forward, but a jet engine doesnt make things fly or lift up.- wings do!
Airflow OVER the wings (as so many have stated already) generates lift (low/high pressure blah blah).
Knowing a little bit about treadmills, I know that when I run on one, the air around me in the room is STAGNANT, smelly, and humid. There is no airflow blowing against me from any angle.
That plane can be sitting (and keeping up) with a treadmill spinning at Mach 5, but its not going to lift into the air. Basically, there is absolutley NO air circulation, activity, or velocity around the wings whatsoever. PERIOD.
The fact that there are 9 pages of postings about this is sad.