[exelius]

Unfortunately, Crestron-style systems are still the only way to go if you want a system that you don't have to babysit too much. They support wireless or wired HDMI across multiple inputs and outputs. But they're pretty expensive (a few thousand dollars per room) so most people don't bother.

Something like Chromecast works ok, but there's no easy way to swap back to other inputs (e.g. a game console) without a remote. Chromecast also has some significant input lag (a second or two) when issuing commands to it.