On Thursday, January 12th, 2012, at 14:11:52h +0900, Brenda Ann wrote:

Most don't use 1080p, opting for 720p with an additional channel or two.

The "standard" for North American terrestrial transmissions is
1080i not 1080p, or as you say 720p@60.

The bandwidth of the UHF channels (6 MHz) is inadequate for 1080p@60.

A possible compromise is 1080p@30, or for movies 1080p@24
but not terrestrial TV transmissions in North America use
this mode.
See the list of official ATSC modes at

http://www.hdtvprimer.COM/ISSUES/what_is_ATSC.html

In Europe where the mains frequency is 50 Hz as opposed to the
North American 60 Hz, the TV norm is similarly 50 Hz, and the
equivalent resolutions are 1080p@25 and 1080p@50.

Again because there is not sufficient bandwidth for 1080p@50,
broadcasters use either 720p@50 or 1080i. The BBC on terrestrial
transmissions has started dynamically switching the transmission mode
on their BBC HD station from 1080i to 1080p@25 and back when it is
appropriate for picture content (material recorded on location
as opposed to studio content).

http://www.reghardware.COM/2011/05/23/bbc_hd_1080p/

This caused a problem for some SONY televisions.

http://www.engadget.com/2011/05/23/bbc-hd-quietly-begins-broadcasting-in-1080p-but-not-all-sony-hd/

A check on Wikipedia reveals that some North American stations
on satellite do broadcast 1080p@24 or 1080p@30 as appropriate.

Please note that the maximum resolution supported by BluRay
is 1080p@24, or 1080i@50 or 1080i@60, bit *not* 1080p@50 or 1080p@60.