This was announced at CES around January. The thread about it's release can be found
here. And CoolerMaster have their own vendor forum here which has some info about the release date
here. According to the second post, both the QFR Stealth and the XT were supposed to come out in May/June 2013 (so right around now). The Stealth was released recently but had some hangups described
in this post. That might have led to XT delays as well. Finally, if you check out the CoolerMaster vendor forum, you can keep track of most of the stuff they'll be coming up with soon. Rajiv and Carter are pretty active members on GH and they work directly for CM Storm.
Edit: You might want to change the OP title as well because I thought you had done a review on the XT