During their Gamescom stream this morning, Xbox finally confirmed that their cloud gaming service will launch on Xbox X|S and Xbox One ‘this holiday’. The feature would enable subscribers to the Xbox Game Pass Ultimate service, to play games utilising their internet connection, without requiring they download and install them locally.
Xbox promise that at launch over 100 games will be supported in the Xbox Game Pass library, which can theoretically be booted instantly without having to wait for the usual download/update process, to get into games with friends as soon as possible. Games like Sea of Thieves, Microsoft Flight Simulator, Minecraft Dungeons, The Medium, Destiny 2 and Forza Horizon 4 have been confirmed already for the service.
Update: As outlined in this chart here, at the moment Australia will not be supported for cloud gaming. The site does detail countries which will support the feature, however, including the US and UK.
You can check out the video Xbox released below: