Nearly every surname origin book I have seen has given the origin as "dweller near the pine tree" or similar. It may well be, but the origins of the name go much further back. An American genealogist by the name of Moses Taylor Pyne did some very detailed research at the beginning of the 20th century,which he published in a couple of books. He had access to Devonshire wills, which are no longer available to us since the second world war.
MT Pyne had the theory that the name originated in Devonshire, from a single knight, who seems to have materialised out of nowhere. Pyne's theory was that this knight, Sir Herbert de Pyns, or de Pins, came to England with Eleanor of Aquitaine when she married Henry II. His theory bears fruit when you find a noble family of the same name living in Aquitaine.
Pyne did a lot of research into this French family, which seems to have been a branch of a northern Spanish house, de Pinos. This family originated in the Pyrenees behind Barcelona. In a town called Baga, there is a large statue of Galceran de Pinos, who helped to defeat the Moors in the area.
When one looks at the demographics of the name in England, there is almost certainly a Devon origin to the name, and almost all of the other instances before the 19th century can be explained.
The name has gone through several changes, mostly due to geography. De Pinos in Spain, de Pins in France, de Pins/de Pyns/de Pyne in medieval England, through to Pyne and Pine today.
My own family line changes from Pine to Pyne in the 1700's, seemingly due to an ancestor moving from one place to another.
Sorry for the long-winded answer, but I get excited when someone asks about the origin of the name.

Darren