otus(4) only supports the AR9170 chip which is a completely different beast than the AR9271. The AR9271 chipset is not supported by OpenBSD, it would require a new driver. It is supported under Linux by the ath9k_htc driver so it would be possible to add support in OpenBSD by reusing code in athn(4). The AR9271 is not very interesting though, it didn't make it into a lot of products, is expensive, and these big USB dongles are boring and ugly. All the 802.11 USB devices made by Atheros have been quite disappointing.
Damien
