Merlin Entertainments Group
2017 - Ninjago World / Ninjago: The Ride - (1/4/17) Legoland Windsor has confirmed that the park’s Ninjago: The Ride and surounding Ninjago themed area will open in May 2017. In addition to the ride it will also include: Cole's Rock Climb, Zane's Temple Build and Kai's Spinners.
(3/29/16) According to a post at Themeparks-UK, Legoland Windsor has plans to open their own Ninjago World, with the "Ninjago: The Ride" interactive dark ride at the park for the 2017 season. They have already submitted the building application for the new land and attraction which will replace Loki's Labyrinth on the backside of the Vikings' River Splash, and require the Longboat Invader to be moved to a new location.
I’m not sure what effect these new plans will have on the previously approved plans to build Ghost: The Haunted House in 2017 (see above). It’s possible they may have scrapped those plans in favor of the larger Ninjago project.
???? - Ghost: The Haunted House - On Hold - (12/1/15) The long delayed plans to build a “GHOST” haunted house attraction at Legoland Windsor have now been approved after a lengthy appeal process by the park. The original proposal intended to build this in 2015 as a copy of the Ghost attraction that opened at the Billund park in 2014, which has a pair of small drop towers built inside what looks like a haunted house exterior, and a lengthy but themed walk-through haunted house queue experience on the way to the ride portion of the attraction.
You can find some layout artwork showing off how the new attraction will look in the Windsor park as well as the approximate location over at a report by Themeparks-UK. Look for this to open in 2017 unless plans change again.
(6/16/15) LEGOLAND Windsor is still attempting to alter their plans for the GHOST haunted house / drop ride project that was denied building permission in 2014. According to ThemeParksUK, the revised proposal, if approved, would see it built for the 2017 season. Other future plans in the works include an expansion of Duplo Valley and an expansion to the LEGOLAND Resort Hotel that would replace the existing Dino Safari ride. If approved, the hotel expansion would also be complete in 2017. The park has also bought part of the St. Leonards Farm next to the park to allow for future expansion projects like a possible EcoLodge project.