Heck, yes!
We've been watching previews for a couple of months, now. I'm totally sick of them and I'm starting to hold a grudge against the movie, because of them. Too much darn marketing!
I don't think it will be a comedy any more than Close Encounters was (not really making a parallel between the two movies except the level of jokes you can include without it becoming a comedy).
I think it will create a surge in believers in crop circles as non-hoaxes. And I think it will create a surge in crop circles.
Still, it's scifi and I'm an addict.