Well, I was watching the commentary on the pilot episode, and creator Eric Kripke actually mentioned Harry Potter.
I believe it was the first time we see inside the Impala's Trunk of Awesomeness and Weaponry. Kripke talked about how the show is supposed to be down-and-dirty, how the Winchesters have to improvise and make do and generally do things the hard way. "It's not like Harry Potter," he said. Essentially, he was making the point that where Harry and co. have spells for just about every little thing, the boys don't get any luxuries or shortcuts.
Which made me think about my poll, and imagine Sam and Dean watching one of the HP movies on cable late at night, and mocking it soundly. :-)
Of course, I also thought about the amulets against possession that Bobby gives the boys at the end of "Born Under a Bad Sign," and wonder if that strayed a tad from the show's hardcore template. (I thought those were totally tacked in, and that annoys me. May they return later, if only to justify their existence.)