The only commercial source that I know of is Rockytop Gardens in TN.
I found a description in their online catalog for 2008 at the following website:
Unfortunately I don't know if it was previously described on this listserve a few years ago.
I took one photo at Linda and Merle Roberts' garden in 2007 in Washington state and the other photo in 2008 in a private garden that will be part of the Spring 2009 AIS Region 13's garden tour. I'm guessing that this iris has also been distributed to other AIS 2009 spring regional garden displays.
It is a stunning iris and seems to be quite hardy at this latitude. I hope people will look for it this spring. I'd love to know how it does in the southern U.S.