I'm not a big fan of things like this -- generally, the more you mess with your brand image, the less prestige you can claim is still attached to it. Themed jerseys are fine for the minor leagues because, well, they're the minor leagues.
Oh, and most importantly: The jerseys are auctioned off for charity. All proceeds go to the Islanders Children's Foundation. As sanctimonious as I can get about staying true to your original threads and the tradition wrapped therein, all that ends when you're raising cash for good causes. Sports fans and their money soon part; might as well redirect some of it toward the betterment of society.