For those who may be interested, just found out that there won't be a stand alone North American Discworld con next year. However, it will be represented as part of Worldcon which is going to be in Spokane, WA. The info is here:
http://it-bodes.blogspot.co.uk/2014/04/announcing-dates-and-location-for-north.html
http://it-bodes.blogspot.co.uk/2014/04/announcing-dates-and-location-for-north.html