The park has to be one of the most heavily studied "wilderness" areas in the world. Living here in Bozeman I've always kept a casual eye open for any info that pertains to the park. There have been all kinds of studies going on that are more or less summed up in that video. If the goal is to have a relatively diverse ecosystem (in the park) that is somewhat balanced and as "wild" as that particular section of land can be then I don't think there is any question that wolves are good for Yellowstone. However the park boundaries are imaginary and with the human population increasing at a pretty fast rate in the area I don't think it's accurate to think of the park and the greater Yellowstone ecosystem as "wilderness". I guess it depends on your definition. Outside the park wolves are definitely a problem for humans. Way less elk around to harvest, predation on cattle, sheep, whatever.. Wolves are being managed in Montana and there is a hunt. http://fwp.mt.gov/hunting/planahunt/huntingGuides/wolf/ For all the gnashing of teeth and hyperbole spewed over wolves in Montana this was always the goal. As far as anecdotal evidence goes I can definitely tell that there are a lot more willows and browse around the drive by creeks and rivers in the park than when I first moved here in '85. On 191 by Snowflake Springs on the Gallatin just outside the park boundary there used to be what IIRC was called an Elk Exclosure. It was a high fenced in area in the river bottom, maybe a 1/5 of an acre, that the elk, deer and moose couldn't get into. The vegetation inside was dense and tall where as outside it was heavily browsed down to a couple of feet. I'm not sure if the fence is even there anymore but the surrounding area is way, way more dense than it was back in the 80s and early 90s. I'm sure that's due to way less elk and moose around. There is also something going on with moose throughout the rockies, I've heard figures like their numbers have dropped by 50% regardless of whether wolves are around or not.