Agreed, they have certainly not cannibalised Disney's numbers, I don't think anyone claimed they have, or ever predicted they would though. Only Disney would know if they are seeing different trends, i.e. guests with shorter stays, or days they go off-site.
What we could never know, if would Disney guests have grown far more had it not been for the developments at Universal.
I don't get the fascination people have for constant growth, there is absolutely nothing wrong with consolidation. Especially if it follows a period of significant growth.
The chase for constant growth is why half the world goes into meltdown when it doesn't occur, our economies are far too reliant on growth occurring in order to be sustainable.
Even on this measure, you don''t need 3% growth in visitor numbers if you can increase in-park spending by the same factor...in fact doing so is far more efficient and is what Disney is chasing. As for stagnation, the one place that isn't happening right now is at Universal, stand in one place and you'd get stuck in wet concrete as a new ride is being built. WDW has the parks that have stagnated, I still love them but so little has changed in 10-15 years it's incredible. Even the announced changes....wow a TSMM and Snorin' expansion, yawn. Avator will hopefully be amazing, even if no-one cares about the IP. Hopefully it hasn't been value engineered to within a nickel of its life.
I actually think Nintendo could be a massive as Potter, if not bigger. Not everyone will agree I know, but not everyone likes Potter (personally, I'm no fan of it). Who knows what other IPs could deliver the same kind of growth in the future or what will be developed? Who though Potter would be worth $15 billion in 15 years time, when in 1997 the publisher didn't like the authors name, gave <$5,000 advance and had a print run of just 500 books?
Other IPs? We know Nintendo and a Marvel expansion. Star Trek has been rumoured.
Nintendo replacing KidZone
Fallon/30 Rock replacing Twister
Fast and Furious replacing Disaster
Ministry of Magic replacing Fear Factor
Something in the MIB/Springfield mystery plot
Something to replace Shrek/Lucy
Updates for T2, E.T. and Mummy (rumored)
JP/JW revamp (using the Discovery Center and the rest of the Trikes plot)
possible Hogsmeade revamp (if they ever decide to remove DC... not likely. MoM is likely the last major Potter-based addition)
MSHI expansion (Doom and Carnage bulldozed, Hulk revamped, new theming/facades)
Toon Lagoon revamp/retheme
Lost Continent revamp/retheme
Seuss expansion
nighttime show for IOA
Volcano Bay (water park)
Sapphire Falls
Cabana Bay expansion
3-5 more resorts
Possible new CityWalk-esque complex
Eventual 3rd gate
Universal is going to surprise some people... USF should be past 9 million for 2015 if it increases a little bit less than this year. IOA should get to almost 8.5 million due to HE spillover.
2016 should definitely see both parks past 9 million.
By 2018, both could potentially be past 10 million - might even be a foregone conclusion! Kong + F&F + Fallon + water park +Sapphire Falls + Diagon spillover + Nintendo + Avengers + whatever else Universal comes up with=higher and higher attendance.
I don't see Universal's attendance declining anytime soon. They've got too much momentum and enough people haven't visited Universal Orlando to where it will continually seem fresh to almost all visitors.