As promised by Alienware before, the WiHD kits are now available while configuring your R3.
Available option are:
Internal WirelessHD Technology FullHD Video Transmitter - 99$
Vizio XWH200 Universal WirelessHD Video and Audio Kit with internal 60Hz WirelessHD Transmitter - 289$
Here's what i found after a brief research.
To stream WirelessHD you obviously need both transmitter and receiver.
Modern TVs should start coming out with the receiver bundled but for the rest both are required.
That means the first option won't give WiHD capabilities because you are lacking the receiver.
Second option comes with both the internal transmitter (option A) plus the commercially available Vizio XWH200 kit (199$ on Amazon) which includes the said receiver and a 4 ports external transmitter to which you can plug your BD/Xbox/PS3 etc.
So for those of us that ordered the R3 before that option was available the only option is to purchase the Vizio (or competing offerings) kit separately and either connect the R3 to the external transmitter or find the internal transmitter.
Dell claims it's only available with new Laptop purchase, any idea where we can buy one ?