Gaia Data Release 2 is scheduled for 25 April 2018.
A description of the anticipated contents of Gaia DR2 is available at the ESA web site.
Following the Gaia second data release, an interactive gathering is planned to allow scientists to come together and explore the Gaia data. This “Gaia Data Release 2 Exploration Lab” is planned in the last week of June (25 – 29 June), two months after the release, and will take place at the European Space Astronomy Centre near Madrid, Spain.