Found this very tasty. Could not find tamarind in the 2 stores I checked so I subbed lime juice as recommended. The pork itself was good but nothing to write home about, but the pineapple chutney was what really made the dish.
The Tamarind Pork is nice, but absolutely not the take-away from this recipe. The Pineapple-Ginger Chutney is a stand-alone keeper that after your first make you'll want to pair with other dishes on your own. If possible, fresh pineapple is the way to go as it allows for a longer cooking time and thus a better reduction. Let it sit for at least 6 hours if you can to really infuse all the flavors and make sure it's room temp when used.
I've made this twice now, once with pork and another time a slight variation using skin-on chicken breasts. It's definitely the salsa that really shines - deliciously fresh and sweet but with enough kick to make it interesting & a nice compliment to pork/chicken. Pictures of my attempt w/ chicken are here: http://www.frenchponytail.com/2011/04/a-springtime-pineapple-massacre/