The account purporting to belong to the Tibetan spiritual leader was only a few days old, but had already attracted tens of thousands of followers. To date, it's probably the most high-profile case of a bogus Twitter account actually getting the boot from the service.
Fake accounts that spoofed media personality Ira Glass and comedian Stephen Colbert gained notable followings until they were unmasked. In both of those cases, the impersonators offered to give the accounts to the real Glass and Colbert, but do not appear to have transferred ownership.
In the case of the Dalai Lama account, Twitter executives said that the decision to nix it was because it violated the company's terms of service. The account, after all, actually claimed to be real: its inaugural "tweet" was, "Welcome to the official Twitter page of His Holiness the Dalai Lama--administered by The Office of His Holiness the Dalai Lama." The AFP story did not give any indication as to whether the real Dalai Lama or his staff had taken issue with the fake Twitter account.
UPDATE at 6:10 p.m. PT: The account is back, but its creator has explicitly acknowledged that it's not an official Dalai Lama Twitter account.