We all seem to be going off into a more "aerodynamic" direction now. So let's keep it open and see if we can keep the semantics lawyers at bay....

If you look at the pressure distribution diagrams for just about any airfoil at some positive angle of attack which is generating a significant quantity of lift it quickly becomes apparent that the area under the charted line for the pressure DROP from the top side is way more than the pressure rise on the bottom side. It may be that the pressure DIFFERENCE is what is supplying the lift but it's pretty clear to anyone looking at those diagrams that the pressure drop over the top surface plays a bigger part than the pressure rise on the lower side.

Something we can play with to get a feel for this is to make sure you Java is up to date and then go play with Foilsim. In particular the pressure distribution readout and how it alters with changes from a very low Coefficient of Lift or Cl value up to the Cl's we get at around 8 to 10 degrees of angle of attack. It's quite the eye opener.

http://www.grc.nasa.gov/WWW/K-12/airplane/foil3.html