A really BIG lens

Sigma has recently introduced a new tele zoom. It's a 200-500/2.8 !! This one is really huge and very heavy. Wonder who the customers for such a lens are? From what I've heard, the weight of this lens is 15kg/30 pound. I think it's too heavy for sports photography. It would be great for wildlife photography, but who is going to drag this monster into the woods? You will also need a rather sturdy tripod. This will probably be at least as heavy as the lens. Well, at least Sigma has got a lot of press coverage. You can read more about it at: http://www.dpreview.com/news/0703/07030805sigma200500mm.asp