Work programmes build the basis for calls under Horizon 2020. Although the Space work programme covering 2016 and 2017 was already published in September 2015, changes could be and were still made. The latest version was released on 25 July 2016 on the participant portal of Horizon 2020. Interested parties should have a look for potential changes in their fields of interest.
Most changes can be seen as minor.
One major change is a completely new introduced Copernicus topic “EO-3-2017: Preparation for a European capacity to monitor CO2 anthropogenic emissions”.
Please also consider those rather minor text changes since this might nevertheless impact your plans for proposals. You should also see if the available budget is still the same since the Commission introduced some shifts here as well.