I am aware that the card has Bluetooth; I was asking about Apt-X in particular. Apt-X is a codec for sending audio over Bluetooth, used instead of the standard SBC codec. It allows for high quality audio over Bluetooth (SBC is phone call quality). Some devices, such as the Samsung Galaxy S3, have Apt-X support built in.
Apologies for reviving an old thread -- since this is the #1 search result on Google, I would like to post a definitive answer to this. So I emailed Killer Wireless and got this reply:
Unfortunately, the apt-x stuff requires a license from CSR. Qualcomm does not hold a license. The A2DP support is base codec and whatever is built into Windows for Win 8/8.1.