Excellent website by Julien Dufour, giving lots of info on hiking and trekking in Northeastern Afghanistan.
John Mock and Kimberley O'Neil on trekking and mountaineering in the Wakhan Corridor and the Afghan Pamir. Although their last visit was in 2007, you may find some useful info here.
Web page about getting to the Wakhan Corridor from Tajikistan, on the Tajikistan Toursim website.
Article in Outside Magazine by Mark Jenkins reporting on a hike through the Wakhan Corridor (2005).