A number of datasets have been used or presented at WSCD workshops.
WSCD2009 participants had access to the Microsoft RFP 2006 dataset, which had search sessions from 2006. Microsoft has decided not to release the dataset again, so unfortunately it is not available for use in new projects.
At WSCD2012 a number of datasets were used and/or announced:
At WSCD2013 has a switching prediction challenge, based on a new set of anonymized Yandex search data.