I don't believe many dates have been announced yet, but here's the short post I share on the Gen Con Indy Facebook group (and update as dates become available).
*** Gen Con 2017 Key Dates ***
Gen Con is Thursday, August 17 through Sunday, August 20.
Badge registration begins on TBD. (Last year was Friday, January 22 at noon ET.)
Housing block (hotel) reservations begin on TBD. (Last year was Sunday, January 24 at noon ET.)
Event registration begins on TBD. (Last year was Sunday, May 15 at noon ET. The event catalog was released on Friday, May 6 at noon ET.)
Pre-registration ends on TBD. (Last year was Sunday, June 19 at 11:59pm ET.)
See www.gencon.com for details.