There's a lot of exciting stuff coming to Disney's (DIS -0.93%) largest theme-park resort in the next few years. Now would be a time to cue up some vintage Tom Petty, because the waiting is the hardest part -- not just for Disney World fans but also for investors. 

Some of the new rides will be replacing existing attractions, and that will translate into prolonged closures. Ellen's Energy Adventure at Epcot will close on Aug. 13, clearing the way for a Guardians of the Galaxy-themed thrill ride. The Great Movie Ride at Disney's Hollywood Studios will also close on that date, eventually to be replaced by Mickey & Minnie's Runaway Railway family attraction.

Epcot has been Disney World's slowest-growing park in recent years, and Disney's Hollywood Studios has slipped to dead last among the resort's four parks in terms of attendance. They're the two places that can use updating the most, but there will near-term pain with the two longtime attractions shutting down forever next month.

Star Wars hotel room concept art.

Image source: Disney.

To infinity and beyond 

There's no denying that a Guardians of the Galaxy ride will be a major draw to what has been a quiet corner of Epcot in recent years. Disney's Hollywood Studios' opening of the first Mickey Mouse-themed ride in the building that is the park's iconic centerpiece will be huge. The rub is that new rides won't open for at least another year or two -- Disney has yet to offer official opening dates -- and the rides that are shutting down to make room for them had high capacity. 

In fact, the Great Movie Ride is one of Disney World's highest-capacity attractions, taking on as many as 2,400 riders an hour. On the other hand, Ellen's Energy Adventure has similar capacity, though it rarely approaches that mark, given weak interest.   

Epcot and Disney's Hollywood Studios were already experiencing declines in popularity, with attendance slipping 0.7% and 0.5% respectively last year, according to Themed Entertainment Association. Things are reportedly getting worse in 2017, as crowd tracker Touring Plans estimates that gains at Disney's Animal Kingdom since May's opening of Pandora -- The World of Avatar have come at the expense of guest counts at Epcot and Disney's Hollywood Studios. 

In theory, this shouldn't matter. Disney's theme-parks segment is still reporting reasonable growth in revenue and operating income, fueled by higher ticket prices and increasing on-site resort capacity. One can also rightfully argue that two parks with dwindling turnstile clicks can withstand the absence of a high-capacity ride for a year or two. 

However, from a vacation-planning perspective, it does make a visit to either property less desirable. Epcot will be fine with its emphasis on seasonal festivals, but Disney's Hollywood Studios -- already earning a reputation as a half-day park -- will be in for a dry spell until Toy Story Land opens next summer. Guests who hit up Disney parks every few years may decide to hold off even longer, waiting until Star Wars: Galaxy's Edge opens in 2019.

Disney World is going to be a pretty special place, cranking out record attendance in the coming years. The waiting, again, is the hardest part.