Bring Back the Buddha :

Almost immediately after the United States forced the Taliban from power at the end of 2001, archaeologists, art historians, and politicians began debating what to do with the site. Afghan president Hamid Karzai calls the reconstruction of the Buddhas "a cultural imperative." Others, such as the French-Afghan archaeologist Zemaryalai Tarzi, say the niches should be left empty to memorialize a dark chapter in the nation's history. Both sides are busily tapping the tools of science and technology as they formulate their vision of how to honor what was, until recently, one of the finest examples of early Buddhist art.

Personally, I say leave them empty.