When I first read this article, it was with a bit of an eye-roll. It made me remember all of the anger that was stirred up with the announcement of AZA and HSUS cozying up last year, too many grumbles about how the fox was now being invited into the chicken coop. After reading it, I'm still not convinced that it isn't a lot of Kumbaya wishful thinking... but wishful thinking is still thinking.
I remember years ago reading, as part of a class, Dale Carnegie's classic book How to Win Friends and Influence People. One of the first lessons that it hammers into the reader is to always get the person who you are disagreeing with to say "Yes" to something, anything. Once you get them in the habit of saying "Yes", it's relatively easy to keep them going.
The truth is, there are a fair number of points in which anyone who care about animals - from AZA to PETA to ethical hunters - should be in agreement on. The need to preserve animals in their natural habitat, the need for people to develop a stronger emotional attachment to the natural world, etc. If we can find ourselves in a position where we agree with people on issues, it'll help to remind everyone involved that the other side isn't - can't be - all bad. From there, a discussion can be had instead of a screamfest.
We'll never always agree on everything. Not even (especially not?) the big things. But it might give us a chance to have a start.