Haiku, if there is a court order stating that the NCP can claim the child with no restrictions (such as being current on CS), then no Form 8332 is needed. You attach a copy of the cover page, signature page (with both parent's signature on it) and the page that states the NCP can claim the deduction. If you have that, then the CP doesn't need to sign a Form 8332.
That is also on the IRS website....
http://www.irs.gov/pub/irs-pdf/p501.pdf
"Divorce decree or separation agreement made after 1984.
If your divorce decree or separation agreement was executed after 1984,
the noncustodial parent does not have to attach Form 8332 if both of the following requirements are met.
1. The decree or agreement is signed by the custodial parent and states all of the following.
a. The custodial parent will not claim the child as a dependent for the year.
b. The noncustodial parent can claim the child as a dependent without regard to any condition, such as payment of support.
c. The years for which the noncustodial parent, rather than the custodial parent, can claim the child as a dependent.
2. The noncustodial parent attaches a copy of the following pages of the decree or agreement to his or her tax return.
a. The cover page (write the other parent's social security number on this page).
b. The pages that contain the information shown in item (1).
c. The signature page with the other parent's signature and the date of the agreement."
Only if it's not listed in the decree does a Form 8332 have to be obtained. My ex and I have done this every tax year since 2000. Neither of us have used Form 8332 because our decree says who claims which child(ren) in what years. He claims 2 every year, I claim one every year.
Edit to add: What I just copied and pasted above starts on page 15 of Publication 501 (at the link above) under
"Support Test for Child of Divorced or Separated Parents"