Epic Games - they of Fortnite, Unreal Engine, and the recently-launched Epic Games Store - have announced that they'll be rolling out a suite of services and tools (as used in Fortnite) to help studios bridge the gap between platforms. Epic recently made waves by getting Sony to reverse their policy on cross-platform play, and have since resumed uniting Fortnite players and accounts across all systems. Epic say the services will be "free for all developers, and will be open to all engines, all platforms, and all stores", which sounds brill, and should help more players get together across age-old boundaries, assuming developers choose to use them.
Throughout 2019 (with most of it due in the third quarter), Epic's tools will be made available to developers, starting with cross-platform login systems, data storage and cloud-saves and expanding to include voice comms all the other gubbins needed to make PCs, consoles and even smartphones play nice with each other. Anything that reduces the number of accounts that need to be juggled. Some things are of obvious interest to players, especially on consoles. Fortnite on the Switch doesn't need to use Nintendo's subscription online service, and its voice chat system is far easier to use than Nintendo's bizarre smartphone-based solution.
As for what Epic get out of this seeming act of benevolence is up for debate, but I feel there's some advantages for them here. It gets developers away from other ecosystems for their voice comms, cloud saves and achievement tracking - all the stuff that major stores like Steam do, but in ways incompatible with Xbox or PlayStation. It also gets studios used to working with Epic's tools, and more likely to do so in future. It also helps wedge open the gap created by Fortnite, ensuring - through Epic's growing clout - that platform holders don't lock down cross-platform play in the future.
So, good for Epic, potentially good for us, and hopefully good for developers wanting to bypass the enormous headache of juggling a half-dozen platforms' individual online quirks. While the roadmap currently only covers 2019, Epic also mention that they're working on support for user-generated content and anti-cheat systems, among others. Level and mod sharing between systems sounds like a dang good thing for me - I remember when Redlynx worked out a cross-platform system for Trials Fusion, and the PC went from a few thousand to hundreds of thousands of user-made levels to pick from almost overnight. Sharing is caring.