Perhaps rhn_register could be modified so that it sets the default value of
State/Province and Country fields according to what locale I use, if possible.

For example, if the system is set to use the sv_SE locale, the country would be
"SE" and the default, pre-filled value of the State/Province and Country fields
would be "Outside the US/Canada" and "Sweden".

I suspect a change like this would result in a lot more reliable state/country
statistics, since people usually aren't prone to change defaults (especially if
it involves scrolling and selecting the correct value from a very long list and
there's no incentitive for them to do so).

I'm attaching sample code for accessing locale information about country.