vicklemos: But I'm very excited about the cross-platform -basically playing windows and linux games together on lan/internet) deal, for the reasons mentioned above :)
As said, I don't see where the Galaxy client would help there? If a game works on Linux, then internet/lan should already be available there?
Cross-play has nothing to do with an inbuilt LAN. Cross-play as GOG mentioned it means you can play your game with your friends, no matter which *store* you buy it from, without any 3rd party clients/accounts (almost direct quote from the Galaxy video)
As far as we're aware there's no LAN enhancement in Galaxy, so there shouldn't be anything you can do when it comes out that you can't already when it comes to that.