Looking on the bright side

There seems to be a recent trend in articles looking on the bright side of introduced species.  In my previous post I linked to the controversial New Scientist article 'Aliens to the rescue', which puts forward the case that there are "Friendly Invaders" and "Alien Species Save Ecosystems".  Another article along similar lines, although without the tabloid phrasing, has now appeared in Conservation Biology:


SCHLAEPFER, M. A., SAX, D. F. and OLDEN, J. D. , The Potential Conservation Value of Non-Native Species. Conservation Biology, EARLY VIEW doi: 10.1111/j.1523-1739.2010.01646.x

Such papers seem to me to be putting forward the 'pros' of introduced species as if the idea that non-natives have benefits is a new thing - but haven't we been growing 'non-native' wheat across the world for thousands of years, introducing bees for pollination etc etc?  This article frustrated me as the way it was conducted reviewed mainly only the positive effects of non-native species, not balancing their examples with negatives.  They do point this out, justifying it by saying such negative cases have been presented elsewhere, but really perhaps they should have put their examples  into context with some balance rather than simply leaning so far to the 'pro-non-native' camp that seems to be emerging.   Perhaps these articles are simply looking for citations, to say 'there are some good things about non-natives, quote...', or maybe academics are setting themselves up a Straw Man - making themselves an easier target to shoot down, by taking the pro- non-native argument to extremes.