They snapped a couple of pics. Here's one of them.
credit: 3rd Man In
To see the other one, check out their blog. By the way, these are not pictures of the jerseys, obviously. I think they said they were t-shirts.
I have no reason to doubt the veracity of these pictures. Notice the silver outline around all of the elements of the logo. That's really the only thing that makes it "new." Otherwise it's just the old logo from the Sabres' early days.
So it's not conclusive evidence, but one more reason to believe that 18 days from now, this is the logo we'll be seeing on the Sabres' new third jersey.