you can agree or disagree - but I think Disney smartly avoided Harry Potter. Many here makes it "Disney vs Universal" but the fact is it is all about "driving tourists to come to Florida". Disney succeeding is not a bad thing for Universal, and the opposite is true for Disney. I've posted on many threads - Harry Potter will be a large short-term boost and small long-term boost for Unviersal. Harry Potter will be a small short-term negative for Disney, but a small long-term boost for them as well.
Here's the scenario: Univeral invents tons of money on HP in both installation and marketing. People flock to Florida to see Harry Potter. But, their in Orlando anyways, what are they gonna do with the rest of their time. Why, Disney of course! Yes, Harry Potter takes *some* business away from Disney but also brings some people to Orlando that wouldn't come otherwise. Win-Win!
And...with Harry Potter - you betcha that you have to pay a continue royalty for the rights to the product. This makes less sense for Disney, who continue to expand their own products. Why have a theme park attraction that makes lots of money that you then have to turn around and pay someone else a big chunk of that profit. No thanks!
So, I think all this thought went into any negotiations...if there were any. Disney would've liked HP - but if JKR was hard-selling them, I don't think the idea of Universal getting it bothered them at all.