When Destiny first arrived in 2014 it was believed that the story of the games would continue on a regular basis with a new game arriving every two years and additional content such as last years the Taken King going in between. This information was pursued by the gaming public based on a ten year deal made between Activision and Bungie which spanned multiple games. So with this you expect to see Destiny 2 this year right? Wrong, Bungie has today announced that we won't see a new full Destiny game until 2017 with an additional lot of content being added during 2016, more particularly sometime during Spring.
In regards to the Destiny sequel beyond the vague 2017 announcement no additional details have been shared, though I would say towards the end of the year might seem right in order to ensure the problems of the original game don't plague the new one. Personally I think they need to include an offline game in the series to at least cater for a much bigger audience and not isolate certain people.