We crossed Khunjerab Pass from Pakistan to China 05.05.2013. According to Pakistani customs log book we were the second ones this year.
No need for N.O.C in the KKH, but police will escort you from Thakot to Dasu. The road in this leg is quite rough too. The road from Dasu to Raikot Bridge is pretty good, after the bridge there are long and heavy road works but mostly brand new tarmac.
We paid 800 rupees for two passengers and one bike to cross Attabad Lake. Loading and unloading are still risky businesses...
After Sost we had to pay 800 rupees each to enter the Khunjerab National Park. The fee is possible to pay in USD or Yuan too. There was lots of snow in Khunjerab Pass and the road was icy with fresh snow... But very beautiful.
Pakistani customs and Chinese border guards want to open and check all your luggage, but we rode alone all the way to Tashkurgan, where we met our guide in the customs house. There was a small snowstorm before Tashgurgan and cold snowy mountains between Tashgurgan and Kashgar.
My English is so limited that I´m not going to tell more about grandness and beauty of the sceneries etc. Amazing road that you have to experience yourself!