Locale problem?

I notice this in the changelog for 5.0-beta5:

- slack: change system default locale to "en_US.UTF-8" and include those locale files in /usr/lib/locale.

However, when I look in /usr/lib/locale, I don't see this directory:

root@Tower:/usr/lib/locale# ls -alrt | grep -i en_US
drwxr-xr-x   3 root root       0 Nov 21  2008 en_US/
drwxr-xr-x   3 root root       0 Feb  4 16:25 en_US.utf8/

Is this right?  The format of that directory name doesn't seem right, and it seems that the default locale (at least on my machine) is "en_US" not "en_US.UTF-8"...

root@Tower:~# locale
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
LANG=en_US
LC_CTYPE="en_US"
LC_NUMERIC="en_US"
LC_TIME="en_US"
LC_COLLATE=C
LC_MONETARY="en_US"
LC_MESSAGES="en_US"
LC_PAPER="en_US"
LC_NAME="en_US"
LC_ADDRESS="en_US"
LC_TELEPHONE="en_US"
LC_MEASUREMENT="en_US"
LC_IDENTIFICATION="en_US"
LC_ALL=
root@Tower:~#