[bombcar]

Lots of US houses have coax to all the main rooms (family, bedrooms) because that was how you got cable TV.

(I still see it in new construction, though if I was having a build done I'd say run multiple Ethernet instead of any coax)

[tkuraku]

I'm just building a new house this year and Ethernet to every room is standard in this area. In a different state in the US coax is standard in new construction. (We just moved) It varies by location.

[bombcar]

Around here it's coax + Ethernet to any "TV" room, Ethernet to all rooms (think - phone line).