The Airlive WMU-6000FS has been on the market for quite a while already so it doesn't feature SATA or Wireless N. However, it is a nice way to reuse an old laptop hard drive when buying an access point. Performance is far from stellar so it won't feed your HD media player with data, it is however perfect for smaller files like office documents, family photos or MP3s.
Feature-wise nothing really lacks. It functions as wireless access point, wireless client. You can set all important settings. Multiple USB devices are supported and can be shared via multiple protocols. Most features are implemented in basic forms though, this keeps configuration relatively simple for the average user though it might limit more advanced users.
Given the fact that a decent access points isn't that much cheaper, the Airlive WMU-6000FS is worth considering unless you really require high performance. Though any wireless connection wouldn't be my first choice anyway with such a requirement.