I have the same question.
But, I use Zorander's wireless-mod.app.bin (ver 0.3), thought it will support Atheros Otos driver.
TL-WN821N should be this:Bus 001 Device 005: ID 0cf3:9170 Atheros Communications, Inc.
I dont know that is or not "Otus“, it just doesnt work.
ifconfig $MDEV up
wpa_supplicant -Bw -Dotus -i$MDEV -c/tmp/mnt/wpa_supplicant.conf
Heard that WDTV Live
support TL-WN821N now, hope it will work in WDTV gen 1 soon.
Or we try to compile our own Linux for WDTV?