Mysterious Press is listed as a "publishing partner" of Open Road Media. But
according to their website their website, they're really a deluxe-limited-edition print-publisher and apparently intend to hand over the conversion to Open Road for the move to digital.
ORM's
webpage for their Ellery Queen offerings is here. Only 2 shown just far, but following the
blog tag for "Ellery Queen" may turn up news of upcoming stuff, since they seem to make announcements with new releases for their other book lines/authors.
Hope this helps.