Marvel island went from being "the place" to go there, to being a land of walk-on rides and no-wait meet n' greets. Universal knows this, and are trying to shift some minor focus to the rides there and updating them (in the least interesting way possible).
The last three times I was at IOA, Spiderman had about an hour wait. So while Potter may be the major reason Universal is seeing significant increases in attendance, it is not reducing the wait times of the other attractions. The only attraction that never seems to have a wait is Dragon Challenge.
Anyone else remember how bad the paint on hulk got while they were completely fixated on Hogwarts? They know where their bread is buttered and it shows.
Actually, rollercoasters are extremely difficult to paint after they've been installed, and Universal didn't want to take it out of service. That aside, the Hulk's paint job had been deteriorating long before they considered building Harry Potter, so let's not pretend IOA is negelcting the rest of the park to focus solely on Potter.
An easy out of Marvel would be beneficial to them so they could work on something new with a clean slate and take some of the pressure off of world-o-potter (crowd management there is atrocious and if they want to do an extension to that area they would likely prefer the guests being sidetracked by something new and awesome). This would be the time to work on such an endevour since like I said previously, people are still magnetically drawn to the other end of the park.
There's nothing Universal can build at the moment that would take the attention away from Potter. And contrary to popular opinion, the Potter area is actually quite large. It's in high demand, that's all. The butterbeer carts are actually the biggest problem for guest flow (I think they should have placed them elsewhere...like in the owlery instead and remove those benches.
On the Disney side of it, They already have been sliding Marvel into anything they can (TV, Disney Stores, etc). If Disney knows anything, they know how to market. I wouldn't be surprised to hear of any plans they already have in motion to find out a way to bring those licenses into the parks. Marvel fans may be all up-in-arms about the whole deal, but in the end, the majority of people (not just Marvel fans mind you) would gladly empty their pockets to get that superhero experience...especially those with kids. Even if the buyout price was high, it could be worth it to them in the long run.
Well if Disney loses the Marvel fans, who pretty much support Marvel's existence, then what would be the point. The characters would be rendered useless, and the excitement of meeting them would diminish since there is no fanbase to keep them in the zeitgeist.
Universal holds the licence and Disney just keeps cashing in on the merchandise regardless. In my opinion..Disney wins in both situations.
Disney actually loses. They only get a small percentage. For Universal, it's business as usual. The only difference is that Marvel has a corporate parent, but for Universal nothing has really changed.
I think Universal really has nothing to lose by selling off the park rights and working on something more original and epic for that faltering section of the park.
Actually, Universal has a lot to lose by getting rid of Marvel. They make money off the merchandise sales too. They benefit from the release of movies and tv shows of Marvel characters.
To their credit they took a relatively small parcel of land and turned it into a theme park phenomenon (like it or hate it..you can't deny the popularity of potterland), and I have no doubts they could figure something out to replace marvel (and no...not DC).
Not to denegrate what they've done, but let's face reality: Potter sells itself. To Universal's credit, they designed it extremely well and included a top-notch thrill ride not seen anywhere else.