As I originally stated, all alleged facts are presumed to be true when ruling on a motion to dismiss. The lower court dismissed the action stating that it failed to state a claim. The Ninth circuit reversed that ruling. Standing was determined based on the allegations, which he later admitted were false.
If I were on the school board's side, I would be filing a Motion for Rule 11 sanctions based on Newdow's televised admissions.
Allowing this claim to continue in light of Newdow's admissions would set a very dangerous precedent. His admission means that the suit violates the "case or controversy" clause of the constitution, since there really was no controversy. I could be wrong but I don't think the court would countenance violating the constitution in order to correct a supposed constitutional violation.
On a practical level, to allow Newdow to continue with this case would open the door to all sorts of "made up" constitutional challenges. Plaintiffs could simply "make up" facts to suit their particular constitutional gripe which is precisely why the "case or controversy" clause exists.