Having arrived home from a screening just in time for the famous CNN focus group of undecided voters, I can only say that it is a strong candidate for the least elucidating form of debate coverage available. Though the media loves to present them as unbiased judges weighing every detail with Solonic precision before making a choice, undecideds are generally low-information voters who haven't paid enough attention to have anything but the vaguest idea what's going on in the campaign at all. The CNN focus group is, by definition, further narrowed down to those undecideds who would like to advertise their lack of knowledge on television. The first few interviewed by Soledad O'Brien essentially offered variations of "I'm not sure I understood what they were talking about" and "All I heard was the same old thing. I want something new."
Taken statistically, the opinions of undecideds are (obviously) extremely important and often quite interesting. Taken individually, as CNN seems to pride itself on doing, not so much.