I may be stating the obvious, but I'll bet that Universal will have a big press event later this year an announce a 12-17 month long 25th Anniversary Celebration.
In the world of theme parks, you can only grab the attention of the national news media once in a while, and what you do has to be big. So I predict they will throw all the major announcements into this one press event. They start off with a sizzle reel recapping this history of Universal, a few "2015" clips from Back to the Future for laughs, etc. Then they will recap the incredible success they have had with HP, Cabana Bay, etc.
Then, they will move onto the new stuff. They will announce the "museum" exhibit, they will announce some sort of Jurassic World thing (I don't know if it's an attraction or a show, but there will be some sort of tie-in), they will announce the water park, they will announce the new hotel, and they will announce Kong. (Side note: the marketing team has their work cut out for them since many casual visitors still think Kong never left).
My point is that all this stuff will be announced at one big media event and rolled into some sort of year-long celebration.
No insider information, just my opinion.