In reply to John Rushby:
ive done several trips in afghanistan over the last 10 years, mostly into wakhan and nuristan.
nowadays its gotta be via tajikistan as the route thru khyber and jalalabad is pretty dubious.
the previous crossings thru lowari in chitral and northern NWFP are also dubious and probably no longer open to foreigners.
there is a possibility of entering wakhan from the chupersan, but it needs a lot of redtape untangling down in islamabad with time-consuming checks from kabul. even then it can always go sour actually at the border. if it works out tho, its way way easier than going thru khorog and ishkashim.
as said above, wakhan is outside of the whole 'afghanistan' thing.
true, the nastiness has crept closer over the last 3 years with kunduz getting less secure, but it hasnt spread any further.
ishkashim has the occasional flare up but its not really directly part of the whole greater security issue - the areas so ethnically diverse that tension has gotten out of hand periodically for decades.
the tajikistan route is rough but a great route in itself. getting to tajikistan is a mish-mash of odd flights and/or epic overland routes. its a cool country with a weird place in history and global politics.
the usual remote area climbing stuff applies: high level self sufficiency, zero evac options, high reliance on local liasons, hygiene etc.
what tajikistan/wakhan has that sets it apart from almost anywhere else is the exit plan. no heading back down to namche for a shower or lhasa to a 4 star, then an easy flight homw.
its the whole long process again, tho this time exhausted.
its totally doable, just factor in enough realistic time and contingencies.