The HD broadcasts are 4:2:2, more often than not. There are a few stations that have their video servers down at 4:2:0, but many of those are scheduled to upgrade over the next 2 years.

Edit: The servers are 422, but the broadcasts are 420, as brigade points out. (The edit tag on my original comment has already expired. Grrr.)

I'm admittedly not familiar with other countries, but I would be incredibly surprised if any of them allowed 4:2:2.

I've assumed that the video settings of the server is what they were delivering, but there must be a down-sample on the way to the transmitter. (Cablelabs is the other large distribution format that we encounter, which yields the same story.)