Last week, I read an interesting article in the Diario Vasco that danced around this very question, which will be addressed tonight in a meeting between some of the great heads and the new faces of basque cuisine, such as Juan Mari Arzak (arzak), Pedro Subijana (akelarre), Iñigo Cojo (a fuego negro) and Andoni Luis Aduriz (mugaritz), just to name a few.
Some of the factors they attributed new basque cuisine's success to were cooperation, innovation, and the "human" factor. One of the organizers of the event said, "Our chefs pollinate with other cultures, like the french, and were able to adapt the basque tradition, finding a balance between international influence and respect for the tradition itself." Also a major factor cited (and one corroborated by a friend of mine who has his hand in the gastronomic scene here) was the cooperation and lack of selfishness on the part of the great chefs here. It's a crowded scene here when it comes to Michelin stars, which makes the lack of ego almost eerie.