Is the New Leica 100-400mm Lens a Sigma Clone?

It's not even 9am when I'm writing this article, and I've already barked sighs of dashed hopes. As I sit here paging through the press info about the new Leica 100-400mm f5-6.3 SL lens, I'm also searching for a sign of hope. If you're savvy, you know one of the darkest secrets in the photo world: all the manufacturers share parts with one another. Further, a few companies more or less make the lenses for every brand, with a few exceptions. In my mind is one question: Is the new Leica 100-400mm f...