Here are some information regarding the upcoming Kamen Rider x Kamen Rider OOO and W feat. Skull Movie Taisen CORE.
Kamen Rider OOO: Nobunaga's Desire
Oda Nobunaga's mummy while wearing an armor was discovered, and the Kougami Foundation decided to do a revival experiment, creating the homunculus named Nobunaga. He was then put under Eiji's care but when Nobunaga's mind was filled with desire for revenge, due to his original thirst for conquering, Eiji must stop him before it is too late.
It is said that Nobunaga will be Kamen Rider Birth (The rumored Bassu).
Kamen Rider W feat. Skull
While Akiko and Terui are preparing for their wedding, Shotaro and Philip encountered the Pteranodon Yummy that has a Gaia Memory called Memory Memory. It is said that this Memory has somehow the ability to look at Sokichi Narumi's past revealing to us his first Dopant related case and how he became Kamen Rider Skull.
Movie CORE
Using the Memories of the past Riders that utilize a huge energy is the appearance of a horrible Rider, Kamen Rider Core. To stop him, W must go deep into the center of the Earth. Along with OOO, in the bottom of the magma, the fierce battle between Core commenced, with Core showing his immense power.
Kamen Rider Core will be made in full CGI.
The screenwriters of this upcoming film will be Riku Sanjo (W feat. Skull) and *sighs* Toshiki Inoue (Nobunaga's Desire).
Source: OCN, alternate-zer0, DecaEnd, HellKaiserAndy, Wikipedia, CSToys Blog
According to our source, DecaEnd, these information that came from OCN can be considered legit because they somewhat work for Toei. Let's just wait for the official announcement before we celebrate.
UPDATE: Added a better translation coming from CSToys Blog.