The article suggests that skeptics believe the Luneau bird is an "abnormal pileated woodpecker". Personally, since late August 2005, I've said that the Luneau bird is likely to be a normal Pileated Woodpecker. This post (about Cornell misinterpreting out-of-focus vegetation as a perched Ivory-bill) came a few days later.
You may remember Zimmer from this posting last month. Note some good comments on Zimmer's own blog posting here.