Despite a showdown with his museum’s biggest benefactor several months ago, Guggenheim Museum director Thomas Krens hasn’t ratcheted down his ambitious plans. “The key to his business plan is hiring big-name architects to design buildings that will become tourist destinations in themselves, like the Guggenheim’s Frank Lloyd Wright building on Fifth Avenue or its Frank Gehry-designed Guggenheim in Bilbao, Spain. And though the museum’s new leaders express caution about the budget, they share Mr. Krens’s vision.”