When we ate there last Sept. our waitress informed us that "the tenderloin today is the fillet", which leads me to believe that the menu really changes according to what they have that week. And it was melt in your mouth good!
While printing "fish of the day", or as the Wave puts it "today's sustainable fish" is common on lots of menus, I think listing "beef of the day" might not sit well with most patrons in what is billed as a mid/upscale dining location. Sort of sounds like the mystery meat you had in high school. I do wish they'd be more specific and not just call it tenderloin.