It depends if you are referring to the wheels traveling at the exact opposite velocity as the conveyor or the plane traveling at the exact opposite velocity as the conveyor.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in the opposite direction)"
(I am referring to it as a treadmill here)
If you are talking about the wheels, then they would be rolling forward at 5mph while the treadmill goes in reverse at 5mph. (The plane doesn't move)
If you are talking about the plane moving forward at 5 mph while the treadmill goes in reverse at 5mph, than the plane would eventually run off the end of a limited treadmill. This would mean the wheels were actually spinning at 10mph.
If the first is true, than there would be no lift, if the second where true (at higher speeds of course), than there would be lift.