While I agree statistics can be used to mislead, I think he's very open about his intepretations of the data.

In his FAQ:
"What do the terms "strong," "weak," and "barely" mean?
By definition, "strong" means support of 10% or more; "weak" means 5% to 9%, and "barely" means less than 5%. The states marked barely are statistical ties."

Also, I would read:
http://www.electoral-vote.com/info/polling.html
Where he says:
"In the first above example, with a 3% MoE, the 95% confidence interval for Kerry is 49% to 55% and for Bush 45% to 51%. Since these overlap, we cannot be 95% certain that Kerry is really ahead, so this is called a statistical tie. Nevertheless, the probability that Kerry is ahead is greater than the probability that Bush is ahead, only we cannot be very sure of the conclusion. When the ranges of the candidates do not overlap (i.e., the difference between them is at least twice the margin of error), then we can be 95% certain the leader is really ahead."

I think anyone looking at ANY statistics needs to take it upon him/herself to understand how the interpreter sliced and diced it to give you the view you're seeing, because polling is inherently "fuzzy math". Personally, that he backs up all the stats he puts up there with explanations of how he arrived at the final numbers along with the actual source data feeds is far more intellectually honest than almost any other polling/estimations that I've seen on the web.