Thats because it gets the position of the vertex in relation to the center of the object, not the center of the world. If you go into edit mode and move the verities and then go out of edit mode and rerun the script it will print different values.
import bpy
import Blender
# Assumes your object is named Plane
ob = Blender.Object.Get('Plane')
me = ob.getData(mesh = True)
obMat = ob.matrix
for v in me.verts:
print obMat * v.co
Will print in world coordinates. You have to use the matrix because the object could be rotated, scaled, or translated relative to the world (just adding the location of the object will only account for the translated part).