I bought a TP-Link 300Mbps High Gain Wireless N USB adapter (TL-WN822N) today (20110813). 

I plugged it into my Ubuntu 11.04 (64-bit) desktop system and disabled all other network connections.

The system recognised the new USB adaptor and began using it. Initially it said I had a 6Mbps connection, but soon ramped up to 117Mbps (see below). No configuration effort was required other than what I have described above.

An iwconfig produces: 

wlan1     IEEE 802.11bgn  ESSID:"Android"            Mode:Managed  Frequency:2.437 GHz  Access Point: 00:60:64:33:9C:56             Bit Rate=117 Mb/s   Tx-Power=20 dBm             Retry  long limit:7   RTS thr:off   Fragment thr:off          Power Management:off          Link Quality=70/70  Signal level=-5 dBm            Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0          Tx excessive retries:0  Invalid misc:74   Missed beacon:0

As you can see, it has a WPA2/PSK encrypted, 117Mbps wifi connection with my Netcomm "N300" ADSL2+ modem / router. 

"lsusb" reports: 

Bus 001 Device 009: ID 0cf3:1002 Atheros Communications, Inc. TP-Link TL-WN821N v2 [Atheros AR9001U-(2)NG]
The network seems to stable and very fast. I haven't tested all the finer functions, but for connectivity it's at least as fast as my 100Mbps ethernet wired connection. 

Posted here so Google can find it.