Aspect of the Hare has a great post up about "Freezing Arrow for non-Hunters" -- of all of the new Wrath abilities, Freezing Arrow seems right up there with Death Grip as a game changer during instance pulls. But as great as it is (a Hunter can now trap a mob at a distance, which means trapping casters is much, much easier), there are drawbacks that you other group members need to know about, hence AotH's post.
First and foremost, chain trapping is out. On a normal trap, a Hunter can lay down a trap early, and get past the extra 10 second cooldown on getting the trap up again, which means they can have another trap pick up the same mob when the first one finishes its duration. But pulling with Freezing Arrow means you can't lay down the trap early, which means that the 10 second cooldown will always be in effect: there will be ten seconds after the trap comes up before the Hunter can Freezing Arrow again.
There are loopholes, as AotH says: Resourcefulness can help Survival Hunters with the cooldown a bit, and Readiness means a Hunter can throw out two Arrows in a row (but no more than that). And of course positioning helps a lot -- if a Hunter can lay down a Freezing Arrow early and then kite a mob into it, chain trapping is theoretically possible (though with casters, it's going to be really tough, just because you have to move so much to get them to move after you). But non-Hunters beware: Freezing Arrow is good for trapping a mob for about 20 seconds. After that, you're on your own.