Here’s a Wired article from last year on assisted migration (or colonization) for species endangered by climate change, as discussed in the previous post. Apparently this is something that at least some ecologists take quite seriously. Obviously, a huge concern is the havoc that such transplants could wreak on their new ecosystems, as Camassia pointed out in a comment. Yet, others argue that, at least in some cases, the risks might be worth it.
The article has some good discussion of the pros and cons of both positions. Echoing Southgate, though, it makes the point that there is no longer any “pure” nature untouched by human influence. Like it or not, the fate of other species is now contingent on our actions (or inaction).