Mixed-winged Warblers?

OK, so you probably recognise the Golden-winged Warbler on the right and the Blue-winged Warbler on the left of the photo collage below. You may even recognise the bird in the middle as a hybrid:

 
A new article in Living Bird magazine discusses a paper in press on the small difference in the genomes of Golden-winged Warbler and Blue-winged Warbler. There are some interesting findings in dominant versus recessive plumage patterns but also the suggestion that perhaps these two should be considered a single species. I am waiting for the article to be published before I come to any conclusion on whether the claims made in the article are warranted but it certainly fodder for thought. Unfortunately this article does not mention the paper's co-authors, which is upsetting, but here is a scan to give you a sense of it: