Kate, here's another link to a thread from this forum:
http://forums.marrowforums.org/showthread.php?t=104
The Laura who responded is the same Laura from Marlene's Aplastic Central link. I don't know if Wendy posted another follow-up to this, but I know her son Grant did not respond to Daclizumab. On the plus side, she said he had no side effects whatsoever, unlike his experience with ATG.
It doesn't sound like this treatment has the rate of success that ATG has, but for a non-responder who is not a good transplant candidate, it can offer some hope of at least some improvement in counts. Laura's temporary partial response is the best I've heard from anybody on the forums, however. I can't remember if Mark (from first thread) eventually tried it or not, but in the interests of full disclosure it should be pointed out that all 3 of these people (Laura, Grant and Mark) ended up going to transplant.