I'm not a Universal fan, but this to me is exactly the reason why Universal shouldn't do LoTR. They should fight the temptation to divert funds to another big name thinking it will draw another 10% increase in ticket sales. Instead focus on building up HP into a great land. In essence, they should learn the lesson that Disney hasn't with DHS.
As for WDW, I'd say much the same thing. The only real place that they could add it is in DHS. However, it's already too much of a mix of other properties. At best, we'll get an Indiana Jones or Star Wars type of treatment - i.e., a single ride or show. I think to do it any real justice, you'd need a major expansion of DHS or even a 5th gate (which I don't want) - Disney is not prepared for that.
As much as I'd love to see it somewhere, I just think it's best left alone.