Currently, all prefectures of the Tibet Autonomous Region (TAR), including Lhasa, are closed to all foreign travelers. Permits stopped being issued last week and the reports from Lhasa indicate that permits will not start being issued again until at least July 25 of this year. Of course, officially Tibet is "open" according to most Chinese consulates, embassies and even the Tibet Tourism Bureau, but in reality it is closed with no permits being issued. If you are looking for any official news of this, you probably won't find it. This year marks the 60th anniversary of the "peaceful liberation of Tibet" and celebrations are scheduled to take place through the TAR. Foreigners are not being allowed to the region in case there are protests (or worse) during the anniversary celebrations. If you have booked a tour to Tibet between now and late July, I strongly suggest contacting your agency for a refund or moving your tour to later this summer or fall when the area reopens.
- Losang, Life on the Tibetan Plateau blog
Losang also reports that many areas of Tibetan Sichuan in the west and north of the province are currently closed to foreign travelers. It looks like China is planning to celebrate the 60th anniversary of the "peaceful liberation of Tibet" by keeping most Tibetan areas as closed armed camps inaccessible to world travelers.