NY Times has a great interactive graphic of Miami and OKC shooting by location on the court (roll over the face pictures to get the actual graphics).
It provides some insight as to why the NBA game seems to be all threes or points in the paint -- the mid-range jump shot just does not have the same return on investment (ie points per shot). Which begs the question, I suppose, as to why anyone shoots the mid-range jump shot at all (look at Battier's and Hardin's maps - they are almost all threes and layups/dunks). I suppose the answer likely takes the form of "you have to shoot mid-range to open up the other two zones", a sort of run to set up the pass in football strategy. Don't know enough about basketball to say if this is true.
Update: Also, the shot clock probably has a lot to do with it. Given infinite time, teams would be able to get the shot they want, but in 24 seconds sometimes you just have to loft one up as time runs out from wherever you are.
Here are the stats: Close range -- 1.19 points per shot, 3-point -- 1.08 pps, mid-range -- 0.80 pps