Davin de Kergommeaux has just reported in his newsletter that Masterson's has expanded its line with a straight barley and straight wheat release. No further details are given on the mash bill compositions, but you can see images of the new bottles on the Masterson's web site. These should be on the shelves now or very soon. I haven't seen any taste notes yet on the web, but maybe there are some.
A very interesting development and a chance to see what some of the non-rye flavoring whiskeys (or that type at any rate) are like.