As the comments on the story point out, it's not really accurate to call this a "discovery". It's pretty much a discovery in the same way that I "discovered" the Eiffel Tower when I went to Paris. It's one of the main things tourists travel to that part of Tunisia to see.
Also, I believe those are the remains of the sets used for Episode II in 2000-01, not from the original filming in the 1970s. From what I recall, when they went back to shoot the prequels, Lucas agreed to leave the sets in tact because the area had become such a tourist destination, and people were disappointed that there wasn't more to see from the movies.
Also, Captain, the underground house scenes from the homestead were shot in a hotel, so you could totally bone in Luke's bedroom. It doesn't have the greatest reviews, though:
http://www.tripadvisor.ca/Hotel_Revi...vernorate.html