Jamie over at AnimeChicago.com received a cease and desist email on July 26, 2013 from Big Tent Entertainment LLC. Apparently the Domo Con convention organizers never got permission to use the Domo-Kun property from Big Tent Entertainment LLC.
Read the full article and keep watch for updates at AnimeChicago.com
Update at 8:40pm on July 26: We just received word from Ryan Kopf. The convention is being renamed to Con Alt Delete and will still take place December 13-15. There is no official word on what alterations will occur beyond the rename. Kopf also stated that use of a common Japanese word like “domo” lead to unnecessary confusion and it was never their intention to purposefully infringe on intellectual property rights.
Update at 8:40pm on July 27: The folks at AnimeCon.org (including Kopf) sent a notice to their email subscribers on the newly renamed convention, Con Alt Delete. No other changes to the convention itself have been announced.