If I'm not mistaken, and this is my biggest worry. It is less about the reintroduction, (they are already moving in on their own), but more about how Colorado will plan to manage the populations. We need to focus on making clear guidelines for what constitutes "reintroduced" we need to be able to take them off the endangered list here ASAP, and be able to regulate their populations via normal North American Wildlife Conservation models.
If we can't manage the populations, we'll for sure see negative effects on elk, moose, and deer populations before they have a chance to change their habits based around a new, formerly absent predator. We haven't had a pack hunting threat in the Colorado mountains for a very long time. The animals here don't remember what it is like to run from those kinds of threats. They'll be at a major disadvantage for a good period of time before they learn to change their habits to accommodate the new threat.
I'm no expert, and no biologist, I know there are some benefits to having them, and some negatives. The other main issue with reintroduction in Colorado, is the fact that we already have a booming and arguably over-populated lion and black bear population set. And Colorado is trying to further restrict predator hunting which is going to further cripple, not only undulate populations, but also hunter contributions and conservation fund loss because fewer people will have desire to hunt here now.